2,220 results on '"Nguyen DQ"'
Search Results
152. Intra-abdominal femoral nerve reconstruction following excision during right hemicolectomy.
- Author
-
Barrett MD, Nguyen DQ, and Boyce DE
- Subjects
- Cecal Diseases surgery, Debridement, Femoral Neuropathy etiology, Fibrin Tissue Adhesive therapeutic use, Humans, Male, Middle Aged, Tissue Adhesives, Colectomy adverse effects, Femoral Nerve surgery, Femoral Neuropathy surgery, Intraoperative Complications surgery, Plastic Surgery Procedures methods
- Abstract
Iatrogenic femoral nerve injury is an uncommon but recognised complication of abdominal and gynaecological surgery. There have been several reported cases following colorectal surgery which specifically report transient femoral nerve neuropathies with variable but often full recovery. To our knowledge, this is the first documented case of femoral nerve reconstruction after iatrogenic resection during right hemicolectomy. We present a case report of complete femoral nerve transection following abdominal surgery and discuss our management., (Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
153. Nasal infection due to Mycobacterium fortuitum.
- Author
-
Nguyen DQ, Righini C, Darouassi Y, and Schmerber S
- Subjects
- Child, Preschool, Female, Humans, Mycobacterium Infections, Nontuberculous diagnosis, Soft Tissue Infections diagnosis, Mycobacterium Infections, Nontuberculous microbiology, Mycobacterium fortuitum, Soft Tissue Infections microbiology
- Abstract
Introduction: Mycobacterium fortuitum, a rapidly growing non-tuberculous atypical mycobacterium, is commonly found in soil and water. This organism generally causes skin, bone, and soft tissue infections following local trauma or surgical procedures, and in immunodeficient patients. The case reported here is, to our knowledge, the first published report of M. fortuitum nasal infection., Case Report: The authors report the case of a 3-year-old girl with intranasal tumour-like swelling associated with cervical lymph nodes due to M. fortuitum infection., Discussion/conclusion: A combination of radical surgical debridement and prolonged therapy with several antimicrobial agents was required to completely eradicate the infection. This case report indicates that non-tuberculous mycobacterial infections should be considered after failure of conventional antibiotic therapy or when classical microbiological tests fail to identify the pathogen responsible for sinonasal and cervical infections., (Copyright © 2011 Elsevier Masson SAS. All rights reserved.)
- Published
- 2011
- Full Text
- View/download PDF
154. Nonsurgical volumetric upper periorbital rejuvenation: a plastic surgeon's perspective.
- Author
-
Liew S and Nguyen DQ
- Subjects
- Female, Follow-Up Studies, Humans, Middle Aged, Cosmetic Techniques, Eyelids, Hyaluronic Acid analogs & derivatives, Rejuvenation
- Abstract
In the aging process, upper periorbits can be divided broadly into two groups. Group 1 is characterized primarily by soft tissue ptosis of the upper eyelid, which requires surgical excision. The patients in group 2, show volume depletion of the soft tissue and bony resorption of the orbit, characterized by deflation of the upper eyelid as well as sunken, hollow, and skeletonized orbits. Currently, structural fat grafting is the only means for adding volume the depleted upper periorbit. It is, however, an invasive procedure associated with fairly significant morbidities, long downtime, and hence poor patient acceptance. The advent of safe hyaluronic acid (HA)-based dermal filler has, in the authors' opinion, revolutionized treatment for this group of oculoplastic patients. In the current series, 36 patients with volume depletion of the periorbit were treated with HA dermal fillers to restore the smooth arc of the upper periorbit. The average volume required ranged from 0.2 to 0.6 ml of filler. Despite the relatively small volume required, the upper periorbital aesthetics of the patients were successfully and dramatically transformed. At this writing, the longest follow-up period has been 3.5 years, with the patient still maintaining periorbital volume. No significant morbidities occurred. Given the multiple risks and the resistance of patients to structural fat grafting compared with HA dermal fillers, the authors believe that this nonsurgical technique for adding volume to the periorbit should become the method of choice for this group of oculoplastic patients.
- Published
- 2011
- Full Text
- View/download PDF
155. The 2009 Sydney shark attacks: case series and literature review.
- Author
-
Rtshiladze MA, Andersen SP, Nguyen DQ, Grabs A, and Ho K
- Subjects
- Adult, Amputation, Traumatic pathology, Amputation, Traumatic surgery, Animals, Bites and Stings pathology, Bites and Stings surgery, Emergency Medical Services, Hand Injuries pathology, Hand Injuries surgery, Humans, Leg Injuries pathology, Leg Injuries surgery, Male, New South Wales, Replantation, Tourniquets adverse effects, Amputation, Traumatic therapy, Bites and Stings therapy, Hand Injuries therapy, Leg Injuries therapy, Sharks
- Abstract
Background: There were 59 unprovoked shark attacks worldwide in 2008. Twelve of these occurred in Australia, ranking it as second only to the USA. In February 2009, two attacks occurred within 72 h in Sydney, Australia., Methods: The two patients involved survived severe limb trauma. Case 1 suffered bite trauma to the lower limb and hand and underwent staged debridement and early amputation. Case 2 presented with a hand severed at the level of the wrist that was initially replanted. However, it would succumb to progressive necrosis after 12 days. We discuss the aspects of these cases that contributed to the patients' survival and ultimately good functional outcomes., Discussion: New paradigms for the management of major trauma patients have emerged over the last decade. We consider recent advances in the understanding of pre-hospital tourniquet use, rapid transit to the operating suite and damage control surgery, and examine how they impacted on the management of our patients. Very little is known about the microbiology of shark bites. Organisms from sea water, the patient's skin and the shark's mouth must all be considered when selecting appropriate antimicrobial prophylaxis. The planning of definitive surgery in severe limb trauma is dependent on the interactions of a number of factors including physical, psychological and social issues. The decision to ultimately replant or amputate the effected limb is best made in union with the patient and their family., (© 2011 The Authors. ANZ Journal of Surgery © 2011 Royal Australasian College of Surgeons.)
- Published
- 2011
- Full Text
- View/download PDF
156. Ionic liquid-assisted carboxylation of amines by CO2: a mechanistic consideration.
- Author
-
Shim YN, Lee JK, Im JK, Mukherjee DK, Nguyen DQ, Cheong M, and Kim HS
- Abstract
The catalytic roles of ionic liquids (ILs) in the syntheses of 1,3-disubstituted ureas from the carboxylation of amines by CO(2) were experimentally and theoretically investigated. The carboxylation reaction of n-butylamine was greatly facilitated by the presence of an IL and the catalytic activity of the IL was strongly affected by the nucleophilicity of the anion. Computational study on the mechanistic aspects of the carboxylation with methylamine with or without the presence of an IL, 1-ethyl-3-methylimidazolium chloride, implies that the activation energies of the transition states and the intermediate ionic species could be lowered significantly through the multi-interactions of the carbonyl group of CO(2) with both cations and anions of the ILs.
- Published
- 2011
- Full Text
- View/download PDF
157. Antiviral treatment following penetrating keratoplasty for herpetic keratitis.
- Author
-
Goodfellow JF, Nabili S, Jones MN, Nguyen DQ, Armitage WJ, Cook SD, and Tole DM
- Subjects
- Administration, Oral, Administration, Topical, Aged, Cohort Studies, Female, Humans, Kaplan-Meier Estimate, Keratitis, Herpetic surgery, Male, Middle Aged, Retrospective Studies, Antiviral Agents therapeutic use, Graft Survival, Keratitis, Herpetic drug therapy, Keratoplasty, Penetrating, Postoperative Complications prevention & control
- Abstract
Purpose: To assess the effect of antiviral treatment on corneal graft survival following penetrating keratoplasty for herpetic keratitis., Methods: Retrospective cohort study of 454 patients receiving primary penetrating keratoplasties (PKs) for viral infection reported to NHS Blood and Transplant (NHSBT) between April 1999 and June 2005. Follow-up data were available on 403 PKs. Kaplan-Meier survival estimates were used to determine graft survival for the three treatment groups: no medication, topical antiviral, and oral antiviral medication. A Cox regression model was used to investigate the combined effects of all additional factors on graft failure. The model was fitted using all pre-operative factors first and then post-operative factors including type of antiviral medication were included., Results: Patients who received oral antiviral medication post-operatively had consistently better graft survival than those receiving no medication or only topical medication. Patients receiving oral antivirals were less than a third as likely to have a failed graft at 5 years compared with those on no antiviral medication (relative risk (RR) 0.3, CI: 0.2-0.7, P=0.002). Other factors that were found to influence the risk of graft failure were the presence of deep corneal vascularisation (P=0.009), PK performed for therapeutic reasons (P=0.03), large diameter grafts (P=0.04), and experiencing a rejection episode (P=0.003)., Conclusion: Oral antiviral treatment reduces the risk of graft failure in patients undergoing primary PK for herpetic keratitis and should be routinely used in this group of patients post-operatively unless contra-indicated.
- Published
- 2011
- Full Text
- View/download PDF
158. Fellowship review: Allergan breast reconstruction fellowship in Vancouver, British Columbia.
- Author
-
Nguyen DQ
- Subjects
- British Columbia, Clinical Competence, Female, Humans, Breast Neoplasms surgery, Fellowships and Scholarships organization & administration, Mammaplasty statistics & numerical data, Practice Patterns, Physicians' organization & administration, Surgery, Plastic organization & administration
- Published
- 2011
- Full Text
- View/download PDF
159. Management of open tibial fractures - a regional experience.
- Author
-
Townley WA, Nguyen DQ, Rooker JC, Dickson JK, Goroszeniuk DZ, Khan MS, and Camp D
- Subjects
- Accidents, Traffic, Adolescent, Adult, Aged, Aged, 80 and over, Child, England, Female, Fracture Fixation methods, Fractures, Open etiology, Humans, Length of Stay statistics & numerical data, Male, Medical Audit, Middle Aged, Postoperative Complications, Prospective Studies, Plastic Surgery Procedures methods, Surgical Flaps, Tibial Fractures etiology, Trauma Severity Indices, Treatment Outcome, Wales, Young Adult, Fractures, Open surgery, Tibial Fractures surgery
- Abstract
Introduction: The treatment of soft-tissue injuries associated with tibial diaphyseal fractures presents a clinical challenge that is best managed by a combined plastic and orthopaedic surgery approach. The current study was undertaken to assess early treatment outcomes and burden of service provision across five regional plastic surgery units in the South-West of England., Subjects and Methods: We conducted a prospective 6-month audit of open tibial diaphyseal fracture management in five plastic surgery units (Bristol, Exeter, Plymouth, Salisbury, Swansea) with a collective catchment of 9.2 million people. Detailed data were collected on patient demographics, injury pattern, surgical management and outcome followed to discharge., Results: The study group consisted of 55 patients (40 male, 15 female). Twenty-two patients presented directly to the emergency department at the specialist hospital (primary group), 33 patients were initially managed at a local hospital (tertiary group). The mean time from injury to soft tissue cover was significantly less (P < 0.001) in the primary group (3.6 ± 0.8 days) than the tertiary group (10.8 ± 2.2 days), principally due to a delay in referral in the latter group (5.4 ± 1.7 days). Cover was achieved with 39 flaps (19 free, 20 local), eight split skin grafts. Nine wounds closed directly or by secondary intention. There were 11 early complications (20%) including one flap failure and four infections. The overall mean length of stay was 17.5 ± 2.8 days., Conclusions: Multidisciplinary management of severe open tibial diaphyseal may not be feasible at presentation of injury depending on local hospital specialist services available. Our results highlight the need for robust assessment, triage and senior orthopaedic review in the early post-injury phase. However, broader improvements in the management of lower limb trauma will additionally require further development of combined specialist trauma centres.
- Published
- 2010
- Full Text
- View/download PDF
160. Clinical phenotype of posterior polymorphous corneal dystrophy in a family with a novel ZEB1 mutation.
- Author
-
Nguyen DQ, Hosseini M, Billingsley G, Héon E, and Churchill AJ
- Subjects
- Adolescent, Adult, Cell Count, Child, Child, Preschool, Corneal Dystrophies, Hereditary pathology, Corneal Endothelial Cell Loss genetics, DNA Mutational Analysis, Endothelium, Corneal pathology, Female, Humans, Male, Pedigree, Phenotype, Polymerase Chain Reaction, Polymorphism, Restriction Fragment Length, Zinc Finger E-box-Binding Homeobox 1, Corneal Dystrophies, Hereditary genetics, Homeodomain Proteins genetics, Mutation, Transcription Factors genetics
- Abstract
Purpose: To describe the clinical phenotype in a family with posterior polymorphous corneal dystrophy (PPCD) and a novel mutation in the ZEB1 gene., Methods: Clinical examination, anterior segment photography, specular microscopy and electrophysiological investigations were performed and quantified. Genomic DNA extracted from peripheral blood was sequenced for ZEB1 exons. Cosegregation of identified mutation with the disease status in the family was confirmed using polymerase chain reaction and restriction fragment length polymorphism., Results: Ocular examination was performed on five family members from two generations. Three had anomalies of the corneal endothelium that were consistent with PPCD. Endothelial cell counts ranged from 2306 to 2987 mm(2) (ref. 2000-4000 cells/mm(2) ). No evidence of glaucoma or retinal abnormalities was observed. Extraocular abnormalities such as inguinal herniation, hydrocoele and possible bony or connective tissue anomalies were part of the disease spectrum in this family. Mutation analysis revealed a novel change in exon 5 of ZEB1 (c.672delA) that cosegregated with the affected disease status., Conclusion: The detailed clinical features of PPCD associated with a novel ZEB1 mutation are supportive of the previously proposed range of phenotype parameters. Further phenotype-genotype correlations may provide insights into the clinical variability and pathological processes affecting the corneal endothelium, Descemet's membrane, retinal photoreceptor function and extraocular tissues of some patients., (© 2009 The Authors. Journal compilation © 2009 Acta Ophthalmol.)
- Published
- 2010
- Full Text
- View/download PDF
161. The DORT solution in acoustic inverse scattering problem of a small elastic scatterer.
- Author
-
Nguyen DQ and Gan WS
- Abstract
The DORT (French acronym for Décomposition de l'Opérateur de Retournement Temporel) method is a novel approach for active detection and focusing of acoustic waves on the targets in the scattering medium. This technique involves the determination of the invariant of the time-reversal operator obtained by measurement of the scattering data in a pulse-echo mode. In this paper, a proposed approach based on the DORT method is developed to solve the acoustic inverse scattering problem of a small metallic scatterer. The proposed approach not only estimates the position of the scatterer, but also determines the physical properties of an unknown metallic scatterer such as the shape (cylinder or sphere), the material (density), and the size (radius) in an anisotropic scattering case. Theoretical and numerical simulation results are also studied and investigated to show that the proposed approach can simultaneously characterize all those properties of an unknown metallic scatterer. Moreover, the advantage of the proposed approach is to avoid the complex iterative scheme in solving the direct scattering problem and results in smaller computational load and faster implementation., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
162. Third-generation continuous flow left ventricular assist devices.
- Author
-
Nguyen DQ and Thourani VH
- Abstract
Tremendous advances have been made in the treatment of end-stage heart failure patients with left ventricular assist devices (LVADs). An important factor playing a role in the improved clinical outcomes is the development of continuous flow, rotary LVADs. New technology using magnetic levitation and hydrodynamic suspension to eliminate contact bearings offers the potential of more durable and efficacious mechanical circulatory blood pumps. Clinical trials evaluating these novel "third-generation" LVADs are in progress.
- Published
- 2010
- Full Text
- View/download PDF
163. Intravenous immunoglobulin (IVIg) in the management of severe refractory vernal keratoconjunctivitis.
- Author
-
Derriman L, Nguyen DQ, Ramanan AV, Dick AD, and Tole DM
- Subjects
- Adolescent, Follow-Up Studies, Humans, Male, Treatment Outcome, Conjunctivitis, Allergic drug therapy, Immunoglobulins, Intravenous therapeutic use
- Published
- 2010
- Full Text
- View/download PDF
164. Spectacle holding local flap modification of free ALT flap.
- Author
-
Nguyen DQ, Rtshiladze M, and Moisidis E
- Subjects
- Aged, 80 and over, Humans, Male, Carcinoma, Squamous Cell surgery, Eyeglasses, Neoplasm Recurrence, Local surgery, Plastic Surgery Procedures methods, Skin Neoplasms surgery, Surgical Flaps
- Published
- 2010
- Full Text
- View/download PDF
165. An objective long-term evaluation of Integra (a dermal skin substitute) and split thickness skin grafts, in acute burns and reconstructive surgery.
- Author
-
Nguyen DQ, Potokar TS, and Price P
- Subjects
- Adult, Burns surgery, Elasticity, Female, Follow-Up Studies, Humans, Male, Middle Aged, Skin physiopathology, Treatment Outcome, Wound Healing physiology, Young Adult, Burns therapy, Chondroitin Sulfates therapeutic use, Collagen therapeutic use, Skin Transplantation methods, Skin, Artificial
- Abstract
Introduction: The field of wound healing and tissue repair has advanced rapidly in the last decade, with this there is an increasing emphasis on the importance of the functional and cosmetic outcomes following injury. Integra artificial skin is the most widely used synthetic skin substitute and is reported to have better outcomes in relation to the appearance and elasticity when compared to split thickness skin grafting (SSG). A review of the literature reveals very few trials that are based on an objective evaluation of Integra treated scars as compared to SSGs. This research aimed to provide objective data on the long-term outcome of Integra., Method: All adult patients from the Welsh Burns Centre who had been successfully treated with Integra+/-SSG were invited to attend a clinic for a follow up provided they had been healed for greater than one year. The hypothesis that Integra scars are more pliable than skin grafts was tested objectively using the Cutometer, a suction device which measures skin elasticity., Results: Of the 13 patients eligible, six were available for assessment. The results of this study suggest that Integra treated sites correlate well with normal skin as measured by the Cutometer. This was statistically significant for the parameters Ur/Ue (elastic function) and Ur/Uf (gross elasticity). On the other hand there was no correlation seen between the patients SSG sites and the patient's normal skin., Conclusion: With advances in medicine we are increasingly able to modulate wound healing and the resultant scars. In order to assess new and often costly treatments the need for objective scar measurement tools have become apparent. Integra has been advocated to improve scarring from injury. However, there have been few studies to evaluate the long-term outcome of Integra as compared to traditional methods such as SSG. In the past scar evaluation has been based on subjective scores by patients and clinicians. Now the mechanical properties of the skin can be evaluated using simple bioengineering methods such as the Cutometer Suction Device. Using this device our study has objectively demonstrated that the elastic properties of areas treated with Integra is comparable to normal skin., (Copyright (c) 2009 Elsevier Ltd and ISBI. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
166. Caspase 3 inactivates biologically active full length interleukin-33 as a classical cytokine but does not prohibit nuclear translocation.
- Author
-
Ali S, Nguyen DQ, Falk W, and Martin MU
- Subjects
- Active Transport, Cell Nucleus, Animals, Cell Line, Humans, Interleukin-33, Interleukins antagonists & inhibitors, Interleukins genetics, Mice, Mice, Knockout, Nuclear Proteins antagonists & inhibitors, Nuclear Proteins genetics, Caspase 3 metabolism, Cell Nucleus metabolism, Interleukins metabolism, Nuclear Proteins metabolism
- Abstract
IL-33 is a member of the IL-1 family of cytokines with dual function which either activates cells via the IL-33 receptor in a paracrine fashion or translocates to the nucleus to regulate gene transcription in an intracrine manner. We show that full length murine IL-33 is active as a cytokine and that it is not processed by caspase 1 to mature IL-33 but instead cleaved by caspase 3 at aa175 to yield two products which are both unable to bind to the IL-33 receptor. Full length IL-33 and its N-terminal caspase 3 breakdown product, however, translocate to the nucleus. Finally, bioactive IL-33 is not released by cells constitutively or after activation. This suggests that IL-33 is not a classical cytokine but exerts its function in the nucleus of intact cells and only activates others cells via its receptor as an alarm mediator after destruction of the producing cell., (Copyright 2009 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
167. Long-term topical steroid treatment after penetrating keratoplasty in patients with pseudophakic bullous keratopathy.
- Author
-
Ross AH, Jones MN, Nguyen DQ, Jaycock PD, Armitage WJ, Cook SD, Kaye SB, and Tole DM
- Subjects
- Administration, Topical, Aged, Aged, 80 and over, Cataract Extraction adverse effects, Corneal Edema etiology, Female, Follow-Up Studies, Humans, Male, Postoperative Care methods, Pseudophakia etiology, Retrospective Studies, Risk Factors, Corneal Edema surgery, Glucocorticoids administration & dosage, Graft Survival drug effects, Keratoplasty, Penetrating, Pseudophakia surgery
- Abstract
Purpose: To assess the use of long-term topical corticosteroid treatment in patients with pseudophakic bullous keratopathy (PBK) after penetrating keratoplasty (PK)., Design: Retrospective cohort study., Participants: This study considered patients with PBK undergoing an initial PK procedure for visual reasons in the United Kingdom between April 1999 and March 2004. There were 1274 initial PK procedures for PBK reported to United Kingdom Transplant in this period, of which 1184 (91%) were grafted for visual reasons. Of these 1184 grafts, follow-up was reported in 1033 instances (87%)., Methods: A Cox regression model was used to investigate the combined effects of all preoperative factors (recipient age, human leukocyte antigen [HLA] matching, trephine size, deep stromal vascularization, surgeon activity) on graft failure. The model was fitted using all preoperative factors first, and subsequently, factors associated with corticosteroid and other medications were included., Main Outcome Measures: Graft survival., Results: Three-year survival of grafts for PBK was 65% (95% confidence interval [CI], 59%-70%). Topical corticosteroids were still being used beyond 18 months after surgery in 378 (37%) of the 1033 corneal grafts included in this study. The grafts of patients not currently receiving steroids were 1.5 times as likely to fail (hazard ratio [HR], 1.5; 95% CI, 1.0-2.2; P<0.03). Lack of HLA matching (P = 0.006), trephine size
or=8.00 mm (P = 0.03), recipient age younger than 65 years (P = 0.003), and corneal vascularization (P = 0.04) all increased the risk of graft failure., Conclusions: The use of long-term postoperative corticosteroids improved graft survival after PK for PBK. Barring patient contraindications for long-term topical corticosteroid use, clinicians should consider maintaining patients with PBK on long-term postoperative corticosteroid maintenance. - Published
- 2009
- Full Text
- View/download PDF
168. Surgical revascularization for cardiac allograft vasculopathy: Is it still an option?
- Author
-
Bhama JK, Nguyen DQ, Scolieri S, Teuteberg JJ, Toyoda Y, Kormos RL, McCurry KR, McNamara D, and Bermudez CA
- Subjects
- Adult, Aged, Aged, 80 and over, Coronary Angiography, Coronary Artery Disease diagnostic imaging, Coronary Artery Disease etiology, Coronary Artery Disease mortality, Female, Humans, Male, Middle Aged, Postoperative Complications, Survival Rate, Young Adult, Coronary Artery Bypass, Coronary Artery Disease surgery, Heart Transplantation adverse effects
- Abstract
Objectives: Cardiac allograft vasculopathy remains a major cause of mortality after cardiac transplantation. Percutaneous revascularization has become the mainstay of therapy given the poor historical outcomes with surgery. Outcomes following surgical revascularization are evaluated to determine whether surgery remains a viable therapeutic option., Methods: A retrospective analysis was performed of 13 heart transplant recipients who had cardiac allograft vasculopathy requiring coronary artery bypass grafting with or without adjunctive percutaneous coronary intervention for revascularization from 1999 to 2008., Results: Thirteen patients had 14 coronary artery bypass grafting procedures at 141 +/- 66 months after transplantation. The average number of grafts was 2.3. Eight were performed without cardiopulmonary bypass, of which 5 were approached via left thoracotomy and the remainder via repeat sternotomy. One patient had renal failure and a cerebrovascular accident. Percutaneous coronary intervention before or after coronary artery bypass grafting was required in 3 patients. There were no perioperative mortalities. At mean follow-up of 39 +/- 36 months, 3 patients have died, 2 from progressive cardiac allograft vasculopathy and 1 from lung cancer. Kaplan-Meier survival for this group of patients was 92%, 83%, and 83% at 1, 5, and 7 years, respectively., Conclusions: Surgical revascularization for cardiac allograft vasculopathy remains a viable treatment option for appropriate patients and may be performed safely with good medium-term outcomes. However, patients remain at risk for disease progression and may require percutaneous or surgical reintervention.
- Published
- 2009
- Full Text
- View/download PDF
169. Forging links between human mental retardation-associated CNVs and mouse gene knockout models.
- Author
-
Webber C, Hehir-Kwa JY, Nguyen DQ, de Vries BB, Veltman JA, and Ponting CP
- Subjects
- Animals, Databases, Genetic, Disease Models, Animal, Gene Knockout Techniques, Humans, Mice, Mice, Knockout, Phenotype, Gene Dosage, Intellectual Disability genetics
- Abstract
Rare copy number variants (CNVs) are frequently associated with common neurological disorders such as mental retardation (MR; learning disability), autism, and schizophrenia. CNV screening in clinical practice is limited because pathological CNVs cannot be distinguished routinely from benign CNVs, and because genes underlying patients' phenotypes remain largely unknown. Here, we present a novel, statistically robust approach that forges links between 148 MR-associated CNVs and phenotypes from approximately 5,000 mouse gene knockout experiments. These CNVs were found to be significantly enriched in two classes of genes, those whose mouse orthologues, when disrupted, result in either abnormal axon or dopaminergic neuron morphologies. Additional enrichments highlighted correspondences between relevant mouse phenotypes and secondary presentations such as brain abnormality, cleft palate, and seizures. The strength of these phenotype enrichments (>100% increases) greatly exceeded molecular annotations (<30% increases) and allowed the identification of 78 genes that may contribute to MR and associated phenotypes. This study is the first to demonstrate how the power of mouse knockout data can be systematically exploited to better understand genetically heterogeneous neurological disorders., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2009
- Full Text
- View/download PDF
170. The visual and refractive outcomes of combined and sequential penetrating keratoplasty, cataract extraction, and intraocular lens insertion.
- Author
-
Nguyen DQ, Mumford LL, Jones MN, Armitage WJ, Cook SD, Kaye SB, and Tole DM
- Subjects
- Aged, Cohort Studies, Female, Graft Survival, Humans, Male, Refraction, Ocular, Retrospective Studies, Treatment Outcome, Visual Acuity, Cataract Extraction methods, Keratoplasty, Penetrating methods, Lens Implantation, Intraocular
- Abstract
Purpose: The aim of this study was to investigate the visual and refractive outcome of combined penetrating keratoplasty, cataract extraction, and intraocular lens insertion (triple procedure) compared with cataract surgery following penetrating keratoplasty (sequential surgery)., Methods: Retrospective cohort study of 1256 first penetrating keratoplasty for Fuchs' dystrophy performed between April 1999 and December 2005. In all, 1202 triple and 54 sequential procedures were reviewed. At 1 year, refractive outcomes were available for 499 triple procedure and 26 sequential surgery eyes. At 2 years, data were available for 264 triple procedure and 10 sequential surgery eyes. At 1 and 2 years postoperatively, graft survival, best-corrected visual acuity (BCVA), spherical equivalent, and cylindrical error were recorded. chi(2)-Tests were used to compare visual outcomes between the two groups., Results: At 1 year after triple procedure surgery, 61% of eyes attained BCVA of >or=6/12, with 47% of eyes within+/-2 D of emmetropia. After sequential surgery, 59% achieved BCVA of >or=6/12 with 67% of eyes within+/-2 D of emmetropia (=0.05). Mean spherical equivalent (MSE) at 1 and 2 years after triple procedure was +1.20 D (SD 5.45) and +0.15 D (SD 3.58), respectively. MSE following sequential surgery at 1 and 2 years was +0.08 D (SD 3.06) and -1.50 D (SD 3.14), respectively. Mean refractive cylinder after combined surgery was +4.16 D (SD 5.11) and +3.91 D (SD 2.79) at 1 and 2 years, respectively, compared with +3.65 D (SD 2.24) and +3.70 D (SD 2.06) after sequential surgery. In all, 29% of triple procedure and 27% sequential surgery eyes had an astigmatic error >or=5.0 D after 1 year (P=0.64), which increased to 34 and 30%, respectively, by the second year. The 5-year graft survival was 85% in both groups. There were no differences in graft survival, visual or refractive outcomes between triple procedure, and sequential surgery techniques., Conclusions: This analysis provided no evidence of improved visual or refractive outcome after sequential surgery compared with triple procedure.
- Published
- 2009
- Full Text
- View/download PDF
171. Keratoconus associated with congenital stationary night blindness type 1.
- Author
-
Nguyen DQ, Hemmerdinger C, Hagan RP, Brown MC, Quah SA, and Kaye SB
- Abstract
A 35-year-old man presented with keratoconus; his best corrected visual acuities were -18.00/+10.00 ×180 (6/60) oculus dexter and -10.00/+8.00 ×5 (6/36) oculus sinister. Bilateral steep central corneal thinning, paracentral ectasia and Vogts striae were present. Normal fundi. Corneal topography disclosed 7.4 dioptres of irregular astigmatism in the central 3 mm with thinning (335 μm). Electroretinography (ERG) showed no response. There were no medical or environmental influences for his keratoconus. Occurrence of keratoconus and congenital stationary night blindness (CSNB) in the patient may represent a chance association, but keratoconus has not been previously linked with CSNB1 either as a chance or true association though both show genetic predisposition.
- Published
- 2009
- Full Text
- View/download PDF
172. Ectomycorrhizal diversity, taxon-specific traits and root N uptake in temperate beech forests.
- Author
-
Khokon AM, Janz D, and Polle A
- Subjects
- Forests, Trees microbiology, Nitrogen, Plant Roots, Mycorrhizae, Fagus microbiology
- Abstract
Roots of forest trees are colonized by a diverse spectrum of ectomycorrhizal (EM) fungal species differing in their nitrogen (N) acquisition abilities. Here, we hypothesized that root N gain is the result of EM fungal diversity or related to taxon-specific traits for N uptake. To test our hypotheses, we traced
15 N enrichment in fine roots, coarse roots and taxon-specific ectomycorrhizas in temperate beech forests in two regions and three seasons, feeding 1 mM NH4 NO3 labelled with either15 NH4 + or15 NO3 - . We morphotyped > 45 000 vital root tips and identified 51 of 53 detected EM species by sequencing. EM root tips exhibited strong, fungal taxon-specific variation in15 N enrichment with higher NH4 + than NO3 - enrichment. The translocation of N into the upper parts of the root system increased with increasing EM fungal diversity. Across the growth season, influential EM species predicting root N gain were not identified, probably due to high temporal dynamics of the species composition of EM assemblages. Our results support that root N acquisition is related to EM fungal community-level traits and highlight the importance of EM diversity for tree N nutrition., (© 2023 The Authors New Phytologist © 2023 New Phytologist Foundation.)- Published
- 2023
- Full Text
- View/download PDF
173. Reduced purifying selection prevails over positive selection in human copy number variant evolution.
- Author
-
Nguyen DQ, Webber C, Hehir-Kwa J, Pfundt R, Veltman J, and Ponting CP
- Subjects
- Animals, Biological Evolution, Chromosomes, Artificial, Bacterial genetics, Databases, Genetic, GC Rich Sequence, Genetic Variation, Genome, Human, Humans, Mice, Models, Genetic, Time Factors, Gene Dosage, Selection, Genetic
- Abstract
Copy number variation is a dominant contributor to genomic variation and may frequently underlie an individual's variable susceptibilities to disease. Here we question our previous proposition that copy number variants (CNVs) are often retained in the human population because of their adaptive benefit. We show that genic biases of CNVs are best explained, not by positive selection, but by reduced efficiency of selection in eliminating deleterious changes from the human population. Of four CNV data sets examined, three exhibit significant increases in protein evolutionary rates. These increases appear to be attributable to the frequent coincidence of CNVs with segmental duplications (SDs) that recombine infrequently. Furthermore, human orthologs of mouse genes, which, when disrupted, result in pre- or postnatal lethality, are unusually depleted in CNVs. Together, these findings support a model of reduced purifying selection (Hill-Robertson interference) within copy number variable regions that are enriched in nonessential genes, allowing both the fixation of slightly deleterious substitutions and increased drift of CNV alleles. Additionally, all four CNV sets exhibited increased rates of interspecies chromosomal rearrangement and nucleotide substitution and an increased gene density. We observe that sequences with high G+C contents are most prone to copy number variation. In particular, frequently duplicated human SD sequence, or CNVs that are large and/or observed frequently, tend to be elevated in G+C content. In contrast, SD sequences that appear fixed in the human population lie more frequently within low G+C sequence. These findings provide an overarching view of how CNVs arise and segregate in the human population.
- Published
- 2008
- Full Text
- View/download PDF
174. Synthesis and antibacterial activity of the C-7 side chain of 3-aminoquinazolinediones.
- Author
-
Hutchings KM, Tran TP, Ellsworth EL, Watson BM, Sanchez JP, Showalter HD, Stier MA, Shapiro M, Themis Joannides E, Huband M, Nguyen DQ, Maiti S, Li T, Tailor J, Thomas G, Ha C, and Singh R
- Subjects
- Combinatorial Chemistry Techniques, Fluoroquinolones chemical synthesis, Fluoroquinolones chemistry, Fluoroquinolones pharmacology, Microbial Sensitivity Tests, Molecular Structure, Structure-Activity Relationship, Anti-Bacterial Agents chemical synthesis, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Gram-Negative Bacteria drug effects, Gram-Negative Bacteria enzymology, Gram-Positive Bacteria drug effects, Gram-Positive Bacteria enzymology, Quinazolinones chemical synthesis, Quinazolinones chemistry, Quinazolinones pharmacology, Topoisomerase II Inhibitors
- Abstract
A novel series of bacterial topoisomerase (3-aminoquinazolinediones) inhibitors are described. The side-chain SAR against Gram-positive and Gram-negative organisms as well as DNA gyrase activity is reported.
- Published
- 2008
- Full Text
- View/download PDF
175. Infants under 1 year of age have a significant risk of burn injury.
- Author
-
Nguyen DQ, Tobin S, Dickson WA, and Potokar TS
- Subjects
- Accidents, Home statistics & numerical data, Body Surface Area, Burns etiology, Female, Humans, Incidence, Infant, Injury Severity Score, Male, Retrospective Studies, Risk Assessment, Sex Distribution, Social Class, Wales epidemiology, Burns epidemiology
- Abstract
A wealth of data exists concerning paediatric burn epidemiology in general, but very little exists specifically in infants under 1 year of age, a special group in which mobility begins to develop. A retrospective study of all burn admissions of infants under 1 year old to The Welsh Centre for Burns from January 2003 to January 2006 was performed. During the 3-year period there were 104 new burns cases identified which represents 11.8% of all paediatric admissions. 63.5% (66) were treated as inpatients and 36.5% (38) treated as out-patients. Burns increased in frequency with increasing age and occurred mainly in the home. Scalds were the commonest type of burn in 65% (68) whilst the second most common was contact burns which accounted for 30% (31). The most common source of scald was from cups containing hot drinks (39%) and the most common source of contact burn was radiators/hot water pipes (30%). The mean TBSA was 2.3%, (range 0.5-38%). The frequency of burns in the under 1 year old population highlights a need for emphasis of burn prevention directed to this group. Special attention is needed to look at the specific aetiology of these burns. Starting points for prevention should address the number of burns surrounding hot drinks and bottle warming practices in the case of scalds and the dangers of household radiators and hot water pipes in the case of contact burns.
- Published
- 2008
- Full Text
- View/download PDF
176. Conjunctival-corneal melt in association with carotid artery stenosis.
- Author
-
Stewart RM, Quah SA, Nguyen DQ, and Kaye SB
- Abstract
Purpose: To report a case of severe conjunctival-corneal melt in association with carotid artery stenosis., Methods: Observational case report., Results: A 76-year-old man with a history of bilateral severe carotid artery occlusion and nonarteritic ischemic optic neuropathy developed a spontaneous bulbar conjunctival defect. Despite intensive lubrication, and attempts at surgical closure including an amniotic membrane patch graft, it progressed with subsequent adjacent corneal perforation. Thorough investigations revealed no underlying disease, except markedly delayed episcleral vessel filling on anterior segment fluorescein angiography., Conclusions: Neovascularisation is a known factor in the inhibition of ulceration. In light of the findings in this report, ocular ischemia should be considered as a cause or contributing factor in the differential diagnosis of conjunctival-corneal melt.
- Published
- 2008
- Full Text
- View/download PDF
177. Repair of nasal soft triangle notching.
- Author
-
Nguyen DQ, Motley R, and Cooper MA
- Subjects
- Adult, Female, Humans, Staphylococcal Infections complications, Nose Deformities, Acquired surgery, Rhinoplasty methods
- Published
- 2008
- Full Text
- View/download PDF
178. A review of current objective and subjective scar assessment tools.
- Author
-
Nguyen DQ, Potokar T, and Price P
- Subjects
- Attitude of Health Personnel, Attitude to Health, Cicatrix nursing, Cicatrix psychology, Evidence-Based Medicine, Finite Element Analysis, Humans, Nursing Assessment standards, Nursing Evaluation Research, Pliability, Reproducibility of Results, Sensitivity and Specificity, Severity of Illness Index, Skin Pigmentation, Cicatrix diagnosis, Nursing Assessment methods
- Abstract
An ideal scar assessment tool should include both objective and subjective methods aspects of a scar. This review examines the evidence on existing tools, and emphasises the importance of taking the patient's perspective into account.
- Published
- 2008
- Full Text
- View/download PDF
179. In-vivo scanning of Ascher intrastromal corneal ring opacity.
- Author
-
Nguyen DQ, Quah SA, Kumar N, Jacob A, and Kaye SB
- Subjects
- Aged, 80 and over, Corneal Stroma, Humans, Male, Corneal Opacity diagnosis, Microscopy, Confocal, Tomography, Optical Coherence
- Published
- 2007
- Full Text
- View/download PDF
180. Keratectasia as a presentation of surgically induced necrotizing sclerokeratitis (SINS).
- Author
-
Nguyen DQ, Raman VS, Twomey JM, and Luthert P
- Subjects
- Aged, Corneal Diseases pathology, Dilatation, Pathologic etiology, Eye Enucleation, Female, Humans, Keratitis etiology, Keratitis physiopathology, Keratitis surgery, Pain etiology, Pain physiopathology, Scleritis etiology, Scleritis physiopathology, Scleritis surgery, Cataract Extraction adverse effects, Corneal Diseases etiology, Keratitis complications, Keratitis pathology, Scleritis complications, Scleritis pathology
- Abstract
Purpose: A case of keratectasia is reported as a severe presentation of surgically induced necrotizing sclerokeratitis (SINS)., Methods: A 72-year-old white woman had a painful, raised lesion on the superior cornea of her right eye 3 years after uncomplicated extracapsular cataract extraction with intraocular lens implantation. Examination showed a large ectatic area of the superior cornea with inflamed sclera adjacent to the surgical wound, which was diagnosed as SINS., Results: No underlying systemic autoimmune condition or vasculitis was identified on investigation. Progressive painful keratectasia necessitated enucleation, which confirmed on histopathologic examination features of chronic nodular episcleritis and nongranulomatous scleritis with evidence of keratitis and fibrovascular scarring., Conclusion: The predominant inflammatory response in the cornea represents surgically induced necrotizing keratoscleritis (SINK) as a new variant presentation of SINS. Oral corticosteroids and immunosuppressive agents should not be delayed to prevent progressive tissue destruction and poor outcome.
- Published
- 2007
- Full Text
- View/download PDF
181. Genome-wide prediction of matrix attachment regions that increase gene expression in mammalian cells.
- Author
-
Girod PA, Nguyen DQ, Calabrese D, Puttini S, Grandjean M, Martinet D, Regamey A, Saugy D, Beckmann JS, Bucher P, and Mermod N
- Subjects
- Animals, CHO Cells, Chickens, Cloning, Molecular, Cricetinae, Cricetulus, Humans, Mice, Molecular Sequence Data, Transfection, Computational Biology methods, Gene Expression, Genome, Human, Matrix Attachment Regions genetics, Recombinant Proteins biosynthesis, Transgenes
- Abstract
Gene transfer in eukaryotic cells and organisms suffers from epigenetic effects that result in low or unstable transgene expression and high clonal variability. Use of epigenetic regulators such as matrix attachment regions (MARs) is a promising approach to alleviate such unwanted effects. Dissection of a known MAR allowed the identification of sequence motifs that mediate elevated transgene expression. Bioinformatics analysis implied that these motifs adopt a curved DNA structure that positions nucleosomes and binds specific transcription factors. From these observations, we computed putative MARs from the human genome. Cloning of several predicted MARs indicated that they are much more potent than the previously known element, boosting the expression of recombinant proteins from cultured cells as well as mediating high and sustained expression in mice. Thus we computationally identified potent epigenetic regulators, opening new strategies toward high and stable transgene expression for research, therapeutic production or gene-based therapies.
- Published
- 2007
- Full Text
- View/download PDF
182. The use of intra-cameral phenylephrine to prevent floppy iris syndrome during cataract surgery.
- Author
-
Nguyen DQ, Sebastian RT, and Kyle G
- Subjects
- Female, Humans, Iris drug effects, Iris Diseases surgery, Male, Pupil drug effects, Treatment Outcome, Cataract Extraction adverse effects, Intraoperative Complications prevention & control, Iris Diseases prevention & control, Mydriatics administration & dosage, Phenylephrine administration & dosage
- Published
- 2007
- Full Text
- View/download PDF
183. Thimerosal-induced limbal stem cell failure: report of a case and review of the literature.
- Author
-
Nguyen DQ, Srinivasan S, Hiscott P, and Kaye SB
- Subjects
- Amnion transplantation, Anti-Infective Agents, Local therapeutic use, Contact Lenses adverse effects, Corneal Opacity pathology, Corneal Opacity surgery, Female, Follow-Up Studies, Humans, Keratoconjunctivitis pathology, Keratoconjunctivitis therapy, Keratoplasty, Penetrating methods, Middle Aged, Myopia therapy, Reoperation, Thimerosal therapeutic use, Transplantation, Homologous, Treatment Failure, Anti-Infective Agents, Local adverse effects, Corneal Opacity etiology, Limbus Corneae cytology, Stem Cell Transplantation, Stem Cells drug effects, Thimerosal adverse effects
- Abstract
Purpose: To report a case of unilateral total limbal stem cell (LSC) failure and corneal opacification secondary to thimerosal- and contact lens-induced ocular surface toxicity., Methods: Interventional case report and review of the literature on thimerosal-induced ocular surface changes., Results: A 49-year-old woman with a 2-year history of long-term soft contact lens wear developed unilateral total LSC failure and corneal opacification secondary to presumed thimerosal-induced toxicity and contact lens wear. At presentation, best-corrected visual acuities were 20/120 in the right eye and 20/15 in the left eye. The patient underwent a keratolimbal allograft and amniotic membrane graft followed by a penetrating keratoplasty. At the last follow-up, the right eye showed a clear corneal graft with a best-corrected visual acuity of 20/30., Conclusions: Thimerosal toxicity can lead to total LSC failure with secondary corneal vascularization and opacification. Keratolimbal allograft followed by penetrating keratoplasty can be successful in reconstructing the ocular surface in such cases.
- Published
- 2007
- Full Text
- View/download PDF
184. Surgeon's experiences of the intraoperative floppy iris syndrome in the United Kingdom.
- Author
-
Nguyen DQ, Sebastian RT, and Kyle G
- Subjects
- Adrenergic alpha-Antagonists adverse effects, Female, Health Care Surveys methods, Humans, Male, Sulfonamides adverse effects, Syndrome, Tamsulosin, United Kingdom, Intraoperative Complications therapy, Iris Diseases therapy
- Published
- 2007
- Full Text
- View/download PDF
185. Microbial keratitis in keratoglobus-associated vernal keratoconjunctivitis and atopic dermatitis.
- Author
-
Nguyen DQ, Sidebottom R, and Bates AK
- Subjects
- Adult, Anti-Infective Agents therapeutic use, Corneal Edema, Drug Therapy, Combination, Eye Infections, Bacterial diagnosis, Eye Infections, Bacterial drug therapy, Humans, Keratitis diagnosis, Keratitis drug therapy, Male, Streptococcal Infections diagnosis, Streptococcal Infections drug therapy, Conjunctivitis, Allergic complications, Cornea abnormalities, Dermatitis, Atopic complications, Eye Abnormalities complications, Eye Infections, Bacterial etiology, Keratitis etiology, Streptococcal Infections etiology
- Abstract
Purpose: The authors describe a patient with keratoglobus and a history of vernal keratoconjunctivitis and atopic dermatitis who acutely developed corneal hydrops and severe microbial keratitis. The infectious keratitis responded poorly to medical management and resulted in enucleation of the eye., Methods: A 25-year-old man presented with an acutely painful, red left eye. He had an ocular history of keratoglobus in association with vernal keratoconjunctivitis and atopic dermatitis. His visual acuity was light perception in the left eye and 20/40 in the right eye. Ocular examination showed a grossly edematous cornea with breaks in Descemet's membrane, a central infiltrative ulcer, and hypopyon., Results: Corneal scrapings showed gram-positive beta-hemolytic streptococci, for which topical treatment of ceftazidime and benzylpenicillin every 30 minutes by day and night was commenced with an oral course of ciprofloxacin 750 mg twice a day. Despite aggressive therapy, the microbial keratitis progressed, and the hypopyon increased in size. The patient subsequently underwent enucleation of his left eye., Conclusions: This is the first reported case of microbial keratitis with corneal hydrops in a patient with keratoglobus, vernal keratoconjunctivitis, and atopic dermatitis. His ocular and dermatologic comorbidity may have impaired corneal integrity and allowed penetration of organisms, resulting in a severe case of keratitis that responded poorly to medical management.
- Published
- 2007
- Full Text
- View/download PDF
186. Structure-activity relationships of 3-aminoquinazolinediones, a new class of bacterial type-2 topoisomerase (DNA gyrase and topo IV) inhibitors.
- Author
-
Tran TP, Ellsworth EL, Sanchez JP, Watson BM, Stier MA, Showalter HD, Domagala JM, Shapiro MA, Joannides ET, Gracheck SJ, Nguyen DQ, Bird P, Yip J, Sharadendu A, Ha C, Ramezani S, Wu X, and Singh R
- Subjects
- Amines chemistry, Amines pharmacology, Anti-Bacterial Agents chemistry, DNA Gyrase, Gram-Positive Bacteria drug effects, Inhibitory Concentration 50, Quinazolinones chemistry, Structure-Activity Relationship, Anti-Bacterial Agents chemical synthesis, Quinazolinones chemical synthesis, Quinazolinones pharmacology, Topoisomerase II Inhibitors
- Abstract
A series of 3-aminoquinazolinediones was synthesized and evaluated for its antibacterial and DNA gyrase activity. The SAR around the quinazolinedione core was explored and the optimal substitutions were combined to give two compounds, 2r and 2s, with exceptional enzyme potency (IC50 = 0.2 microM) and activity against gram-positive organisms (MIC's = 0.015-0.06 microg/mL).
- Published
- 2007
- Full Text
- View/download PDF
187. Keratoconus associated with CSNB1.
- Author
-
Nguyen DQ, Hemmerdinger C, Hagan RP, Brown MC, Quah SA, and Kaye SB
- Subjects
- Adult, Electroretinography, Genetic Linkage, Humans, Male, Keratoconus complications, Night Blindness congenital
- Published
- 2007
- Full Text
- View/download PDF
188. Releasable conjunctival suture for adjustable suture surgery.
- Author
-
Nguyen DQ, Hale J, Von Lany H, and Harrad RA
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Equipment Design, Female, Follow-Up Studies, Humans, Male, Middle Aged, Prospective Studies, Treatment Outcome, Conjunctiva surgery, Ophthalmologic Surgical Procedures methods, Polyglactin 910, Strabismus surgery, Suture Techniques instrumentation, Sutures
- Abstract
Background: Adjustable sutures are widely used in adult strabismus surgery, with a second procedure performed to close the conjunctiva irrespective of whether adjustment is required. We describe a technique where the conjunctiva is closed using a buried releasable suture, eliminating the second procedure if adjustment is deemed unnecessary., Method: The conjunctiva is closed using a 6/0 absorbable polyglactin 910 releasable suture. It is tied in a bow, like the muscle sutures, and tucked under the conjunctiva. If adjustment is not required, the eye does not need to be touched because the conjunctiva is secured by the suture. If adjustment is required, it is easy to untie the conjunctival suture, allowing good exposure to the underlying muscle sutures., Results: In our prospective series of 30 patients, we found our technique effective and patient friendly. Patients had at least 3 months of follow-up with no significant complications., Conclusions: This technique is acceptable, accessible, and time saving for both surgeons and patients. It is especially useful for anxious patients and adolescents, for whom postoperative manipulation can be difficult, and for cases where the probability of adjustment is low.
- Published
- 2007
- Full Text
- View/download PDF
189. Occupational, environmental, and toxicological health risks of mining metals for lithium-ion batteries: a narrative review of the Pubmed database.
- Author
-
Brown, Connor W., Goldfine, Charlotte E., Allan-Blitz, Lao-Tzu, and Erickson, Timothy B.
- Subjects
ELECTRIC power supplies to apparatus ,RISK assessment ,MANGANESE ,HEALTH status indicators ,ACUTE diseases ,COBALT ,RESPIRATORY diseases ,SYSTEMATIC reviews ,MEDLINE ,LITHIUM ,NICKEL ,NEUROLOGICAL disorders ,CHRONIC diseases ,OCCUPATIONAL exposure ,ENVIRONMENTAL exposure ,MINERAL industries ,METALS ,ONLINE information services ,COMPARATIVE studies - Abstract
Background: The global market for lithium-ion batteries (LIBs) is growing exponentially, resulting in an increase in mining activities for the metals needed for manufacturing LIBs. Cobalt, lithium, manganese, and nickel are four of the metals most used in the construction of LIBs, and each has known toxicological risks associated with exposure. Mining for these metals poses potential human health risks via occupational and environmental exposures; however, there is a paucity of data surrounding the risks of increasing mining activity. The objective of this review was to characterize these risks. Methods: We conducted a review of the literature via a systematic search of the PubMed database on the health effects of mining for cobalt, lithium, manganese, and nickel. We included articles that (1) reported original research, (2) reported outcomes directly related to human health, (3) assessed exposure to mining for cobalt, lithium, manganese, or nickel, and (4) had an available English translation. We excluded all other articles. Our search identified 183 relevant articles. Results: Toxicological hazards were reported in 110 studies. Exposure to cobalt and nickel mining were most associated with respiratory toxicity, while exposure to manganese mining was most associated with neurologic toxicity. Notably, no articles were identified that assessed lithium toxicity associated with mining exposure. Traumatic hazards were reported in six studies. Three articles reported infectious disease hazards, while six studies reported effects on mental health. Several studies reported increased health risks in children compared to adults. Conclusions: The results of this review suggest that occupational and environmental exposure to mining metals used in LIBs presents significant risks to human health that result in both acute and chronic toxicities. Further research is needed to better characterize these risks, particularly regarding lithium mining. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
190. Machine learning model predicts airway stenosis requiring clinical intervention in patients after lung transplantation: a retrospective case-controlled study.
- Author
-
Tian, Dong, Zuo, Yu-Jie, Yan, Hao-Ji, Huang, Heng, Liu, Ming-Zhao, Yang, Hang, Zhao, Jin, Shi, Ling-Zhi, and Chen, Jing-Yu
- Subjects
MACHINE learning ,RANDOM forest algorithms ,FEATURE selection ,PULMONARY arterial hypertension ,LUNG transplantation - Abstract
Background: Patients with airway stenosis (AS) are associated with considerable morbidity and mortality after lung transplantation (LTx). This study aims to develop and validate machine learning (ML) models to predict AS requiring clinical intervention in patients after LTx. Methods: Patients who underwent LTx between January 2017 and December 2019 were reviewed. The conventional logistic regression (LR) model was fitted by the independent risk factors which were determined by multivariate LR. The optimal ML model was determined based on 7 feature selection methods and 8 ML algorithms. Model performance was assessed by the area under the curve (AUC) and brier score, which were internally validated by the bootstrap method. Results: A total of 381 LTx patients were included, and 40 (10.5%) patients developed AS. Multivariate analysis indicated that male, pulmonary arterial hypertension, and postoperative 6-min walking test were significantly associated with AS (all P < 0.001). The conventional LR model showed performance with an AUC of 0.689 and brier score of 0.091. In total, 56 ML models were developed and the optimal ML model was the model fitted using a random forest algorithm with a determination coefficient feature selection method. The optimal model exhibited the highest AUC and brier score values of 0.760 (95% confidence interval [CI], 0.666–0.864) and 0.085 (95% CI, 0.058–0.117) among all ML models, which was superior to the conventional LR model. Conclusions: The optimal ML model, which was developed by clinical characteristics, allows for the satisfactory prediction of AS in patients after LTx. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
191. Rumour detection on benchmark twitter datasets using graph neural networks with data augmentation.
- Author
-
Patel, Shaswat, Bansal, Prince, and Kaur, Preeti
- Abstract
Social media has become a significant source of essential facts and alarming falsehoods, including rumours. A significant increase in rumour spreading has occurred due to the lack of an autonomous rumour detection mechanism, causing widespread and severe social repercussions. To address this challenge, we present a ground-breaking method for developing an automatic rumour detection system, focusing on the fundamental problem of class imbalance in rumour detection. Our method selectively uses oversampling to obtain a uniformly distributed dataset by leveraging contextualised data augmentation techniques to generate synthetic samples for underrepresented classes. Furthermore, we effectively recreate non-linear dialogues inside a thread using two novel graph neural networks (GNNs), which improves the system's capacity to understand complex links between postings. Our method employs a distinctive feature selection mechanism to enhance further Twitter representations based on the state-of-the-art BERTweet model. The thorough analysis of our methodology using three publicly accessible datasets yielded compelling results: (1) our GNN models outperformed the most state-of-the-art classifiers in F1-score by more than 20%. Emphasizing the importance of our approach to developing sophisticated rumour detection systems. (2) By utilizing our oversampling method, we significantly improve the F1-score by 9%, highlighting the practical implications of resolving class imbalance. (3) Our technique delivers further performance increases through non-random selection criteria for data augmentation, with the selection of relevant tweets highlighting the significance of our novel augmentation strategy. (4) Notably, our approach captures rumours in their early stages more effectively than previous classifiers, establishing a baseline for future works. The innovative aspects of our proposed method lie in its ability to solve class imbalance effectively, outperform existing classifiers in terms of performance, and drastically reduce the propagation of rumours and false information on social media platforms. Our study lays the way for developments in rumour detection by offering a comprehensive solution, eventually helping to ensure the veracity of information flowing online. We are confident that our findings have an influence on the broader field of rumour detection systems and provide fresh directions for further study. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
192. GPT-4 as an X data annotator: Unraveling its performance on a stance classification task.
- Author
-
Liyanage, Chandreen R., Gokani, Ravi, and Mago, Vijay
- Subjects
MACHINE learning ,LANGUAGE models ,GENERATIVE pre-trained transformers ,TRANSFORMER models - Abstract
Data annotation in NLP is a costly and time-consuming task, traditionally handled by human experts who require extensive training to enhance the task-related background knowledge. Besides, labeling social media texts is particularly challenging due to their brevity, informality, creativity, and varying human perceptions regarding the sociocultural context of the world. With the emergence of GPT models and their proficiency in various NLP tasks, this study aims to establish a performance baseline for GPT-4 as a social media text annotator. To achieve this, we employ our own dataset of tweets, expertly labeled for stance detection with full inter-rater agreement among three annotators. We experiment with three techniques: Zero-shot, Few-shot, and Zero-shot with Chain-of-Thoughts to create prompts for the labeling task. We utilize four training sets constructed with different label sets, including human labels, to fine-tune transformer-based large language models and various combinations of traditional machine learning models with embeddings for stance classification. Finally, all fine-tuned models undergo evaluation using a common testing set with human-generated labels. We use the results from models trained on human labels as the benchmark to assess GPT-4's potential as an annotator across the three prompting techniques. Based on the experimental findings, GPT-4 achieves comparable results through the Few-shot and Zero-shot Chain-of-Thoughts prompting methods. However, none of these labeling techniques surpass the top three models fine-tuned on human labels. Moreover, we introduce the Zero-shot Chain-of-Thoughts as an effective strategy for aspect-based social media text labeling, which performs better than the standard Zero-shot and yields results similar to the high-performing yet expensive Few-shot approach. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
193. Comparison of combination skin substitutes and skin grafts versus skin grafts only for treating wounds measured by Vancouver Scar Scale: A comprehensive meta-analysis.
- Author
-
Putri, Indri Lakhsmi, Sindhu, Florencia Christina, Aisyah, Imaniar Fitri, Pramanasari, Rachmaniar, and Wungu, Citrawati Dyah Kencono
- Published
- 2024
- Full Text
- View/download PDF
194. Keep your friends close, and your enemies closer: structural properties of negative relationships on Twitter.
- Author
-
Tacchi, Jack, Boldrini, Chiara, Passarella, Andrea, and Conti, Marco
- Subjects
ONLINE social networks ,SOCIAL networks ,SENTIMENT analysis ,STRUCTURAL models ,SOCIAL context - Abstract
The Ego Network Model (ENM) is a model for the structural organisation of relationships, rooted in evolutionary anthropology, that is found ubiquitously in social contexts. It takes the perspective of a single user (Ego) and organises their contacts (Alters) into a series of (typically 5) concentric circles of decreasing intimacy and increasing size. Alters are sorted based on their tie strength to the Ego, however, this is difficult to measure directly. Traditionally, the interaction frequency has been used as a proxy but this misses the qualitative aspects of connections, such as signs (i.e. polarity), which have been shown to provide extremely useful information. However, the sign of an online social relationship is usually an implicit piece of information, which needs to be estimated by interaction data from Online Social Networks (OSNs), making sign prediction in OSNs a research challenge in and of itself. This work aims to bring the ENM into the signed networks domain by investigating the interplay of signed connections with the ENM. This paper delivers 2 main contributions. Firstly, a new and data-efficient method of signing relationships between individuals using sentiment analysis and, secondly, we provide an in-depth look at the properties of Signed Ego Networks (SENs), using 9 Twitter datasets of various categories of users. We find that negative connections are generally over-represented in the active part of the Ego Networks, suggesting that Twitter greatly over-emphasises negative relationships with respect to "offline" social networks. Further, users who use social networks for professional reasons have an even greater share of negative connections. Despite this, we also found weak signs that less negative users tend to allocate more cognitive effort to individual relationships and thus have smaller ego networks on average. All in all, even though structurally ENMs are known to be similar in both offline and online social networks, our results indicate that relationships on Twitter tend to nurture more negativity than offline contexts. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
195. FANS: a framework for feature selection in sentiment classification using a modified Firefly algorithm.
- Author
-
Asgarnezhad, Razieh and Monajemi, Amirhassan
- Abstract
Sentiment classification is a prevalent task in text mining in which a text classifies into positive, negative, or neutral classes. Sentiment classification is an essential issue of decision-making for people, companies, etc. Feature selection is the most influential stage in sentiment classification. Due to the NP-hard nature of the problem and a huge of existing texts, the traditional feature selection techniques, such as statistical techniques, generate sub-optimal solutions. Swarm intelligence algorithms are extensively devoted to optimization problems. These algorithms produce features by increasing the classification performance and decreasing the computational complexity and feature set size. In this study, the authors proposed a framework using the modified multi-objective Firefly algorithm, namely FANS (Firefly Algorithm Naïve Bayes Sentiment). The two targets are decreasing the naïve Bayes error classifier and the k-nearest neighbor. A neural network is used as the final classifier. The three datasets on Movie review and Twitter domains are applied to evaluate the FANS. The FANS outperform its counterparts regarding precision, accuracy, and recall. The FANS yields 96.88% precision, 97.65% accuracy, and 96.54% recall. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
196. Process simulation–based scenario analysis of scaled-up bioethanol production from water hyacinth.
- Author
-
Abeysuriya, Dulanji Imalsha, Sethunga, G. S. M. D. P., and Rathnayake, Mahinsasa
- Abstract
Water hyacinth (WH) is an aquatic weed with an experimentally proven potential as a feedstock for bioethanol production. Unlike other bioethanol feedstocks, water hyacinth has no requirement for land use and resource consumption for cultivation. This study evaluates scaled-up bioethanol production process routes, modelled using the Aspen Plus process simulator to analyse the process performance of water hyacinth as a bioethanol feedstock. Four process scenarios are developed by combining two different feedstock pretreatment methods (i.e., alkali pretreatment and diluted acid pretreatment) and bioethanol dehydration techniques (i.e., azeotropic distillation and extractive distillation). Mass and energy flows of the four scenarios are comparatively analysed. Results show that the alkali pretreatment method provides a higher bioethanol yield (i.e., 254 L/tonne-WH) compared with the dilute acid pretreatment method (i.e., 210 L/tonne-WH). In addition, the process route combining alkali pretreatment and extractive dehydration techniques indicates the least process energy consumption of 45,310 MJ/m
3 of bioethanol. The process energy flow analysis evaluates two energy sustainability indicators, i.e., net energy gain and renewability factor, with further interpretation of variation effects of the key process parameters through a sensitivity analysis. The feasible ways of utilising water hyacinth as a fuel-grade bioethanol feedstock for industrial-scale production are discussed. [ABSTRACT FROM AUTHOR]- Published
- 2024
- Full Text
- View/download PDF
197. The Qatar World Cup and Twitter sentiment: Unraveling the interplay of soft power, public opinion, and media scrutiny.
- Author
-
Hassan, Ahmed A. M. and Wang, Jia
- Subjects
SPORTS events ,SOFT power (Social sciences) ,PUBLIC opinion polls ,CULTURAL relations ,SENTIMENT analysis ,PUBLIC opinion - Abstract
This research examines public opinion on Twitter during the 2022 FIFA World Cup in Qatar, focusing on the interplay between sport, communication, and soft power. It sheds light on the online discourse surrounding a global sporting event by analyzing tweet frequency, sentiment changes, prevalent topics, and the most popular tweets surrounding controversial events. Political discussions surrounding the World Cup initially dominated but gradually declined, shifting the focus to sporting achievements and cultural exchange. Throughout the tournament, the host country, European countries participating in the World Cup, and fans contested the narrative surrounding the event. However, the study highlights how celebrities and public figures had a more significant impact on shaping conversations about sports, cultural exchange, and sociopolitical issues. These findings deepen the understanding of the interplay between sports, politics, culture, and social issues, offering insights to researchers, practitioners, and policymakers. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
198. Fast Convergent Stability Sliding Mode Control for Slotless Self Bearing Motor with Consideration of External Load Torque.
- Author
-
Van Hoc, Vu, Giap, Van Nam, and Nguyen, Quang Dich
- Published
- 2024
- Full Text
- View/download PDF
199. Pollution of four heavy metal elements in dried chili peppers in Guizhou Province and its health risk assessment.
- Author
-
Zhou, Li-qiang and Liu, Wen-zheng
- Subjects
HOT peppers ,PEPPERS ,HEAVY elements ,LEAD ,HEAVY metal toxicology ,ARSENIC - Abstract
This study aimed to evaluate arsenic (As), cadmium (Cd), chromium (Cr), and lead (Pb) levels in dried chili peppers from nine districts in Guizhou Province. These heavy metals, widely dispersed and capable of transferring to crops, pose potential health risks to humans. The assessment included modeling daily intake (EDI), target hazard quotient (THQ), total target hazard index (TTHQ), and target carcinogenic risk (TCR) to assess health risks across different population groups. Results showed chromium (0.9540 ± 0.301 mg/kg) and lead (0.8949 ± 0.266 mg/kg) had the highest concentrations, followed by arsenic (0.3287 ± 0.093 mg/kg) and cadmium (0.0627 ± 0.017 mg/kg). Children exhibited higher EDI values than adults, indicating greater health risks from dried chili pepper consumption at equivalent levels. THQ and TTHQ values were below 1 across all regions, indicating no significant health risks associated with dried chili pepper consumption. Similarly, TCR values were below 10–4 for all nine regions, indicating an acceptable level of carcinogenic risk. Overall, consuming dried chili peppers in Guizhou Province poses an acceptable health risk, but caution is advised, especially for children, to limit heavy metal exposure. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
200. A neutrophil elastase-generated mature form of IL-33 is a potent regulator of endothelial cell activation and proliferative retinopathy.
- Author
-
Bisen, Shivantika, Verma, Shailendra Kumar, Mukhopadhyay, Chandra Sekhar, and Singh, Nikhlesh K.
- Published
- 2024
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.