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Laser filament properties, including the plasma induced by the filamenting pulse in the medium, depend on the numerical aperture (NA) of the focusing optics used to create them. Recent studies of this dependence have revealed two distinct linear and non-linear filamentation regimes. Highresolution spatial and temporal electron density measurements are presented demonstrating the transition from the linear to nonlinear focusing regime. This study shows that the dominance of geometrical focusing in the linear (high NA) regime produces plasma with high peak densities and large plasma diameters, while filamentation in the nonlinear regime, equivalent to long distance filamentation, leads to low peak densities and small plasma diameters. [ABSTRACT FROM AUTHOR]

The role of stereotactic body radiation therapy (SBRT) in achieving durable local control and palliation of pain in pelvic lymph node oligometastatic disease is not well-studied. We performed a retrospective analysis of 30 patients with 43 pelvic lymph node oligometastases from various primary cancers all but one with non-prostate primaries treated at our institution with SBRT. The median follow-up time was 21 months. The median SBRT dose was 24 Gy in four fractions. The one-, two-, and five-year local control was 74%, 71%, and 70% and one-, two-, and five-year overall survival was 70%, 47%, and 31%. Toxicities were mild with no grade 3 or higher. [ABSTRACT FROM AUTHOR]

Spatially resolved wavefront measurements are presented during nonlinear self-collapse and provide the first detailed characterization of wavefront evolution during filament formation. The wavefront dynamics of key nonlinear processes including Kerr self-focusing, ionization and plasma defocusing, and dynamic spatial replenishment are identified and resolved in both the filament core and reservoir regions. These results are analyzed and interpreted with respect to numerical simulations and provide insight into fundamental aspects of filamentation. They also inform applications based on phase manipulation, such as external beam guiding, and present a new method for measuring the nonlinear index of refraction, n2. [ABSTRACT FROM AUTHOR]

Background Double-row rotator cuff tendon repair techniques may provide superior contact area and strength compared with single-row repairs, but are associated with higher material expenses and prolonged operating time. The purpose of this study was to evaluate gap formation, ultimate tensile strength and stiffness of a single-row cruciate suture rotator cuff repair construct, and to compare these results with those of the Mason-Allen and SutureBridge repair constructs. Methods Infraspinatus tendons from 24 spring lamb shoulders were harvested and allocated to cruciate suture, Mason-Allen and SutureBridge repair groups. Specimens were loaded cyclically between 10 and 62 N for 200 cycles, and gap formation simultaneously measured using a high-speed digital camera. Specimens were then loaded in uniaxial tension to failure, and construct stiffness and repair strength were evaluated. Results Gap formation in the cruciate suture repair was significantly lower than that of the Mason-Allen repair (mean difference = 0.6 mm, P = 0.009) and no different from that of the SutureBridge repair ( P > 0.05). Both the cruciate suture repair (mean difference = 15.7 N/mm, P = 0.002) and SutureBridge repair (mean difference = 15.8 N/mm, P = 0.034) were significantly stiffer than that of the Mason-Allen repair; however, no significant differences in ultimate tensile strength between repair groups were discerned ( P > 0.05). Conclusion The cruciate suture repair construct, which may represent a simple and cost-effective alternative to double-row and double-row equivalent rotator cuff repairs, has comparable biomechanical strength and integrity with that of the SutureBridge repair, and may result in improved construct longevity and tendon healing compared with the Mason-Allen repair. [ABSTRACT FROM AUTHOR]

Context Good preparation for surgical procedures has been linked to better performance and enhanced learning in the operating theatre. Mental imagery is increasingly used to enhance performance in competitive sport and there has been recent interest in applying this in surgery. Objectives This study aims to identify the mental imagery components of preoperative preparation in orthopaedic trauma surgery and to locate these practices in existing socio-material theory in order to produce a model useful for surgical skills training. Methods Semi-structured interviews were conducted with nine orthopaedic surgeons. Participants were identified by personal recommendation as regularly performing complex trauma operations to a high standard, and by affiliation to an international instruction course in trauma surgery. Interviews were audio-recorded and transcripts were independently analysed using thematic analysis. Results Analysis revealed that surgeons interact intensively with multiple colleagues and materials during their preparatory activities. Such interactions stimulate mental imagery in order to build strategy and rehearse procedures, which, in turn, stimulate preparatory interactions. Participants identified the discussion of a preoperative 'plan' as a key engagement tool for training junior surgeons and as a form of currency by which a trainee may increase his or her participation in a procedure. Conclusions Preoperative preparation can be thought of as a socio-material ontology requiring a surgeon to negotiate imaginal, verbal and physical interactions with people, materials and his or her own mental imagery. Actor-network theory is useful for making sense of these interactions and for allowing surgeons to interrogate their own preparative processes. We recommend supervisors to use a form of preoperative plan as a teaching tool and to encourage trainees to develop their own preparatory skills. The ability of a trainee to demonstrate sound preparation is an indicator of readiness to perform a procedure. [ABSTRACT FROM AUTHOR]

Purpose: Re-establishment of the native footprint during rotator cuff repair is important for maximizing healing potential and fixation strength. The purpose of this study was to evaluate the contact area, contact pressure, stiffness and tensile strength of a new single-row cruciate suture repair and to compare these results to those of the Mason-Allen, double-row and transosseous repairs. Methods: Infraspinatus tendons from fifty-six lamb shoulders were harvested and randomly assigned to cruciate suture, Mason-Allen, double-row and transosseous repair groups. Repairs were performed over pressure-sensitive film and footprint contact area and pressure measured. Repaired tendon specimens were also loaded in uniaxial tension, and ultimate tensile strength and stiffness measured. Results: The cruciate suture repair established significantly greater footprint contact area compared to the Mason-Allen repair (mean difference = 101 mm, p = 0.003). The ultimate tensile strength and stiffness of the double-row repair was significantly higher than that of all other repair groups ( p < 0.05). The average footprint contact pressure of the cruciate suture repair (0.78 MPa) was similar to that of the Mason-Allen (0.74 MPa) and double-row repairs (0.79 MPa). The ultimate tensile strength of the cruciate suture repair was significantly greater than that of the transosseous repair (mean difference 62.4 N, p = 0.002). Conclusion: The cruciate suture repair may improve strength and healing at the repaired tendon rotator cuff insertion relative to other single-row repair techniques. It may represent a faster, easier and more cost-effective alternative to double-row repairs. [ABSTRACT FROM AUTHOR]

Filamentation is favorable for many long-range outdoor laser applications, some of which require propagation to or at high altitudes. Understanding how the filamentation process and filament properties are impacted by the low pressure conditions present at high altitudes is essential in designing effective applications. The scaling of filament preconditions with pressure is considered. An increase in critical power and decrease in transition numerical aperture (NA) is predicted to occur with a drop in pressure, indicating that nonlinear pulse propagation and filamentation at high altitudes requires higher energy and a longer assisted focal length than sea level filamentation. A summary of pressure-scaled filament properties is also presented. New simulations demonstrate filamentation at pressures as low as 0.0035 atm (38.5 km altitude) is possible. [ABSTRACT FROM AUTHOR]

There is an increasing trend towards operative treatment for displaced midshaft clavicle fractures. This retrospective study was performed to assess the outcome of delayed fixation of displaced midshaft clavicle fractures and test the null hypothesis that there is no difference in results between early and delayed surgical treatment for displaced midshaft clavicle fractures. Using the hospital database, two groups of patients who were surgically treated using Herbert cannulated screw for displaced midshaft clavicle fractures were identified. There were 114 cases in acute (median time to operation of 5 days) and 21 cases in delayed groups (median time to operation 10.5 weeks). Thirty-five cases were available for follow-up in the acute and 16 cases in the delayed series. The primary outcome was assessed by the Disabilities of the Arm, Shoulder and Hand (DASH) score, American Shoulder and Elbow Surgeons score (ASES) and Constant-Murley score. Union occurred in 14 cases in the delayed group. The median DASH, mean ASES and Constant-Murley scores were 4.1, 97 and 88.7, respectively. Compared with the delayed group, the early group had a higher union rate ( P = 0.033), trend towards lower DASH score ( P = 0.051), and higher ASES score ( P = 0.047). The delayed group had significantly more problems with prominent, symptomatic screws that required removal ( P = 0.002). There were no significant differences in union time and complication rate. Delayed fixation of displaced midshaft fractures using the Herbert cannulated bone screw and bone graft is effective and provides a good functional outcome that only slightly reduced from that recorded for early fixation. [ABSTRACT FROM AUTHOR]

Background: Reverse total shoulder arthroplasty changes the lines of action of the shoulder muscles, resulting in increases in the moment arms of the major abductors and flexors of the glenohumeral joint; however, at present little is known about the axial rotation capacity of the musculature after this procedure. The purpose of this study was to measure the instantaneous axial rotation moment arms of all of the major muscles spanning the glenohumeral joint during abduction and flexion after reverse total shoulder arthroplasty. Methods: Reverse total shoulder arthroplasty was performed on eight entire cadaveric upper extremities. Specimens were mounted onto a testing apparatus, and the internal/external rotation moment arms of eighteen major muscle subregions involving the subscapulars, supraspinatus, infraspinatus, teres minor, teres major, deltoid, pectoralis major, and latissimus dorsi were measured during abduction and flexion. These muscle moment arms were compared with those measured preoperatively in the anatomical shoulders (i.e., before the arthroplasty). Results: Reverse total shoulder arthroplasty resulted in loss of external rotation function in the posterior deltoid sub-region. Postoperatively, the inferior subscapulars subregion had the largest internal rotation moment arm overall, whereas the teres minor and the inferior infraspinatus subregion had the greatest external rotation moment arms. The teres minor, infraspinatus, and deltoid subregions were external rotators during abduction, whereas only the teres minor, infraspinatus, and to a small extent the posterior deltoid subregion were external rotators during flexion. Conclusions: Reverse total shoulder arthroplasty results in an overall decrease in the external rotation moment arm of the deltoid and increases in the moment arms of the major internal rotators, including the latissimus dorsi and pectoralis major. Reverse total shoulder arthroplasty may result in complete loss of external rotation function if the teres minor and infraspinatus muscles are damaged. Clinical Relevance: Care should be taken to avoid damaging the infraspinatus and the teres minor during a reverse shoulder arthroplasty, as these are the only major external rotators after that procedure. Greater external rotation may be achieved postoperatively when the humerus is positioned in the coronal plane rather than the sagittal plane. [ABSTRACT FROM AUTHOR]

The article discusses significance of fever in pediatrics, citing its physiological aspects. It states that fever is one of the three most concerned health conditions for parents of and mentions lack scientific evidence inferring fever itself as a dangerous clinical condition. It notes findings of a cohort study related to association of fever with serious illness in children. It highlights topics like benefits of reducing a child's fever, fever as a natural response of the body to infection.

Background: Acute compartment syndrome is a serious and not uncommon complication of limb trauma. The condition is a surgical emergency and is associated with significant morbidity if not diagnosed promptly and treated effectively. Despite the urgency of effective management to minimize the risk of adverse outcomes, there is currently little consensus in the published reports as to what constitutes best practice in the management of acute limb compartment syndrome. Methods: A structured survey was sent to all currently practising orthopaedic surgeons and accredited orthopaedic registrars in Australia to assess their current practice in the management of acute, traumatic compartment syndrome of the leg. Questions were related to key decision nodes in the management process, as identified in a literature review. These included identification of patients at high risk, diagnosis of the condition in alert and unconscious patients, optimal timeframe and technique for carrying out a fasciotomy and management of fasciotomy wounds. Results: A total of 264 valid responses were received, a response rate of 29% of all eligible respondents. The results indicated considerable variation in management of acute compartment syndrome of the leg, in particular in the utilization of compartment pressure measurement and the appropriate pressure threshold for fasciotomy. Of the 78% of respondents who regularly measured compartment pressure, 33% used an absolute pressure threshold, 28% used a differential pressure threshold and 39% took both into consideration. Conclusions: There is variation in the management of acute, traumatic compartment syndrome of the leg in Australia. The development of evidence-based clinical practice guidelines may be beneficial. [ABSTRACT FROM AUTHOR]

This is the report of a pilot second-year foundation programme in which all trainees experienced a four-month attachment in general practice. There were six trainees and one educational supervisor. The report gives details of the educational background of the programme. There is also an evaluation by trainees and trainers. Five of the six trainees reported that the attachment in general practice was the most useful part of the foundation programme. They found that the attachment improved their basic clinical skills as well as providing an awareness of primary care. Trainers reported that the attachments had mostly been rewarding. The foundation trainees required more supervision than traditional trainees (such as GP registrars). The foundation trainees also differed in their educational requirements in that they were training to develop their general medical skills rather than training for a career in primary care. [ABSTRACT FROM AUTHOR]

Abstract: This paper considers the phenomenon of third party antidumping; that is, the ability of a firm to bring an AD case in a foreign country against third party dumpers. Recent experience in New Zealand is discussed and suggestions are offered as to why a country might wish to permit foreigners to demand that other foreigners increase prices in that country. [Copyright &y& Elsevier]

We consider the simultaneous choice of parallel importing regime and tariff policy in a setting of international price discrimination by a monopolist. We show that an importer''s optimal tariff decreases when parallel imports (PIs) are permitted. This may lead to the monopolist benefiting from PIs. Allowing PIs is always attractive for a country whether or not it sets an optimal tariff. In a political economy modification, we show that the prohibition of PIs is more likely to emerge (where it would not otherwise) the more the government cares about lobby contributions and the greater are profits from price discrimination. [Copyright &y& Elsevier]

Examines the quality and congestion for environmental goods in New Zealand. Enjoyment on local environmental resources; Differentiation between foreign high-value and domestic low-value consumers incur; Congestion costs with common resources; Reduction on the quality of foreign demands.

Presents spectroscopic and laser properties of Neodymium:YCOB and its potential for scaling as a self-frequency-doubling laser to high powers. Optical properties of polarized absorption spectra; Emission cross section; Laser operation using a novel high-power diode system as pump source; Thermal stress fracture limits.

Provides information on a study which examined the efficacy of otoacoustic emissions (OAE) as a screening test for hearing impairment in children with acute bacterial meningitis. Methodology; Results; Discussion.

Laser filament properties, including the plasma induced by the filamenting pulse in the medium, depend on the numerical aperture (NA) of the focusing optics used to create them. Recent studies of this dependence have revealed two distinct linear and non-linear filamentation regimes. High-resolution spatial and temporal electron density measurements are presented demonstrating the transition from the linear to nonlinear focusing regime. This study shows that the dominance of geometrical focusing in the linear (high NA) regime produces plasma with high peak densities and large plasma diameters, while filamentation in the nonlinear regime, equivalent to long distance filamentation, leads to low peak densities and small plasma diameters. [ABSTRACT FROM AUTHOR]

Analyzes the measurements of thermally induced lensing in end-pumped Cr[3+]-doped colquiriites. Details on the colquiriites used in the study; Measurement of focal lengths; Advantages of longitudinal diode pumping of a solid-state laser material; Details on thermal lensing; Details on the study.

Discusses the use of a single-shot laser plasma to generate X-rays similar to synchroton facilities to image live cells of Candida albicans. X-ray microscopy for biological specimens; Derivation of atomic force microscopy from scanning tunnelling microscope; Imaging live hydrated microbial cells by an X-ray optical system.

This article comments on initiatives and debates around authors depositing post-prints of their articles in institutional repositories. Post-prints are not the final article. A widely held definition of a post-print is the final draft of an author's manuscript, as accepted for publication, incorporating referees' suggestions, but before it has undergone the copyediting and proof-correction process. A reader is faced with two copies of the same article at different stages of the publication process. If the author has previously deposited a pre-print on a pre-print server, or on their own personal or institution's Web site, then there is a third version. Citation analysis is also used to assess the quality of an individual author's work, both by their peers, their employers and by grant-awarding authorities. If the trends of self-archiving of postprints continue, it would potentially threaten the revenue streams that underwrite the processes of publication. If, as a result of the widespread use of post-print archives, journals begin to see the sort of declines in paid subscriptions that those offering free online archives are experiencing, this could result in further price escalation that will restrict availability rather than enhance it.

The article offers information underutilized capacity of the private sector surgical training for educating our future surgical workforce. Topics discussed include ways in which performing an appendicectomy requires much more than technical expertise; emergency procedures such as appendicectomy are performed in the public sector; and need of surgical educator.

Background: This study reports the outcomes of a single institutional experience treating non‐small cell lung cancer (NSCLC) involving the pulmonary hilum with low‐dose stereotactic body radiation therapy (SBRT). The authors also present a series of repeat hilar SBRT. Methods: Inclusion criteria required treatment with SBRT for NSCLC involving regional lymph nodes of the: (i) hilum, (ii) mediastinum, (iii) aortopulmonary window (station 5), or (iv) mainstem bronchus. At least one clinical follow‐up with imaging was required, unless the patient had a prior documented death from cancer. Results: A total of 32 patients with 44 treatments were included, and 37 treatments targeted the hilum directly, with seven concerning the mediastinum, AP window, or mainstem bronchus. Median dose was 28 Gy in four fractions with once‐weekly fractionation. At a median clinical follow‐up of 23 months, local control was 64%. Median overall survival was 24 months, and median progression‐free survival was 15 months. A total of 48% of treatments resulted in complete radiographic response on last imaging follow‐up, and no cases of grade ≥ 3 toxicity were reported. For repeat SBRT (after prior hilar SBRT), local control was 92%. Median overall survival was 20 months, and median progression‐free survival was 19 months. Complete radiographic response was noted after 58% of treatments, with 0 instances of progressive response and no reported side effects. Conclusions: Low‐dose hilar SBRT was efficacious and well‐tolerated, with impressive overall survival and no grade ≥ 3 toxicity. Repeat treatments with SBRT were feasible and effective, demonstrating overall survival, local control, and toxicity comparable to primary treatments. Key points: Significant findings of the study: Low‐dose hilar SBRT was efficacious and well‐toleratedRepeated treatments with SBRT demonstrated encouraging results, comparable to primary treatments What this study adds: This study contributes to the small body of literature concerning hilar SBRTRepeat hilar SBRT was safe and feasibleToxicity was minimal with low‐dose SBRTOnce‐weekly fractionation may have contributed to low rate of side effects. [ABSTRACT FROM AUTHOR]

Background: Surgical fixation of comminuted mid‐shaft clavicle fractures commonly employs intramedullary devices; however, pins with smooth surfaces are prone to migration, whilst threaded pins can be challenging to remove post‐operatively. The aim of this study was to evaluate the biomechanical performance of fractured clavicles repaired using a novel intramedullary Echidna pin device and a non‐threaded Knowles pin. The Echidna pin features retractable spines that engage with the bone to minimize migration and facilitate ease of device removal. Methods: A total of 28 cadaveric clavicle specimens were harvested and a mid‐shaft wedge‐shaped osteotomy was performed to simulate a comminuted butterfly fragment. Specimens were allocated randomly to either the Echidna pin or Knowles pin fracture repair groups. Following surgery, eight specimens in each group underwent 200 cycles of four‐point bending, whilst six specimens in each group underwent torsional testing and pull‐out. Cyclic construct bending stiffness, torsional stiffness and ultimate strength were recorded. Results: Echidna pin intramedullary repair constructs showed significantly greater bending stiffness (mean difference 0.55 N.m/°, 95% confidence interval −0.96, −0.14, P = 0.01) and pull‐out strength (mean difference 146.03 N, 95% confidence interval 29.14, 262.92, P = 0.019) in comparison to Knowles pin constructs. There was no significant difference in torsional stiffness between Echidna pin and Knowles pin repair constructs (P > 0.05). Conclusion: The intramedullary Echidna pin device, which exhibits greater bending strength and pull‐out strength than that of the Knowles pin, may produce a more stable clavicle fracture reduction compared to that of commercially available threadless intramedullary pins. [ABSTRACT FROM AUTHOR]

Spectroscopic properties of thulium-doped germanate, silica, and phosphate glasses were measured and compared since such glasses are of interest as materials for fiber lasers in the eye-safe wavelength region. 3F4 excited state fluorescence decay dynamics was investigated at temperatures from 8 to 300 K and the results revealed a strong dependence of the 3F4 lifetime on the host matrix. The temperature-dependent stimulated emission cross section was obtained by using the Fuchtbauer–Ladenburg technique. In phosphate glass the fluorescent lifetime is short, making this material difficult to use for 2 μm laser purposes. Tm3+-doped germanate glass shows a longer lifetime than silica, a comparable value of stimulated emission cross section and some interesting temperature-independent properties. [ABSTRACT FROM AUTHOR]

The authors reflect on the significance of white blood count (WBC) as a tool to determine the treatment order for children with feverish illness by referring to a study by S. De and colleagues. Topics discussed include role of chest X-rays, WBC analysis and urine analysis in determining the treatment order, role of the National Institute for Health and Care Excellence (NICE) guidelines to manage feverish illness, and role of paediatricians in examining children for viral or bacterial illness.

Background: Rotator cuff repair surgery aims to create a secure, pressurized tendon-bone footprint to permit re-establishment of the fibrovascular interface and tendon healing. Flat-braided suture-tape is an alternative suture material to traditional suture-wire that has potential to reproduce a larger repair construct contact area. The objective of this study was to compare contact pressure, area as well as the mechanical fatigue strength between suture-wire and suture-tape Suture-bridge repair constructs in an ovine model.Methods: Sixty lamb infraspinatus tendons were harvested and randomly allocated to three- and four-anchor Suture-bridge repairs performed using either suture-wire or suture-tape. Thirty-two specimens were cyclically loaded for 200 cycles in an Instron testing machine, while tendon gap formation was recorded using a high speed digital motion analysis system. Loading to failure was then performed to evaluate construct ultimate tensile strength and stiffness. The remaining 28 specimens were assessed for repair contact pressure and area using pressure-sensitive film.Results: There was a significantly greater average tendon contact pressure (mean difference: 0.064 MPa, p = 0.04) and area (mean difference: 2.71 mm2, p = 0.03) in fiber-tape repair constructs compared to those in fiber-wire constructs for the three-anchor Suture-bridge configuration. The four-anchor suture-tape constructs had a significantly larger ultimate tensile strength than that of the four-anchor suture-wire constructs (mean difference: 56.4 N, p = 0.04). There were no significant differences in gap formation or stiffness between suture-tape and suture-wire constructs (p > 0.05).Conclusion: Suture-tape offers greater pressurised tendon-bone contact than suture-wire in three-anchor Suture-bridge repairs, while greater mechanical strength is achieved with the use of suture-tape in four-anchor Suture-bridge constructs. [ABSTRACT FROM AUTHOR]

The article focuses on guidelines which have been established by Great Britain's National Institute for Health & Clinical Excellence (NICE) concerning the assessment and initial management of feverish illness in children younger than five years of age. A discussion of risk assessment policies that are contained in the guidelines is presented. Barriers which physicians may encounter when attempting to follow the NICE guidelines, and a leaflet which the Guideline Development Group has created which helps physicians follow the guidelines, are discussed.

Background: Oesophageal perforation is an uncommon surgical emergency associated with high morbidity and mortality. The timing and type of intervention is crucial and there has been a major paradigm shift towards minimal invasive management over the last 15 years. Herein, we review our management of spontaneous and iatrogenic oesophageal perforations and assess the short- and long-term outcomes. Methods: We performed a retrospective review of consecutive patients presenting with intra-thoracic oesophageal perforation between January 2004 and Dec 2020 in a single tertiary hospital. Results: Seventy-four patients were identified with oesophageal perforations: 58.1% were male; mean age of 68.28 ± 13.67 years. Aetiology was spontaneous in 42 (56.76%), iatrogenic in 29 (39.2%) and foreign body ingestion/related to trauma in 3 (4.1%). The diagnosis was delayed in 29 (39.2%) cases for longer than 24 h. There was change in the primary diagnostic modality over the period of this study with CT being used for diagnosis for 19 of 20 patients (95%). Initial management of the oesophageal perforation included a surgical intervention in 34 [45.9%; primary closure in 28 (37.8%), resection in 6 (8.1%)], endoscopic stenting in 18 (24.3%) and conservative management in 22 (29.7%) patients. On multivariate analysis, there was an effect of pathology (malignant vs. benign; p = 0.003) and surgical treatment as first line (p = 0.048) on 90-day mortality. However, at 1-year and overall follow-up, time to presentation (≤ 24 h vs. > 24 h) remained the only significant variable (p = 0.017 & p = 0.02, respectively). Conclusion: Oesophageal perforation remains a condition with high mortality. The paradigm shift in our tertiary unit suggests the more liberal use of CT to establish an earlier diagnosis and a higher rate of oesophageal stenting as a primary management option for iatrogenic perforations. Time to diagnosis and management continues to be the most critical variable in the overall outcome. [ABSTRACT FROM AUTHOR]

A great deal of evidence suggests that partial weight-bearing exercise plays an important role in bone fracture healing. However, current physiotherapy program tends to follow the “Let's try it and see” strategy due to the lack of a fundamental understanding of in vivo mechanical environment required for the better healing outcomes. The purpose of present study is to develop an innovative framework to predict the healing outcomes as a result of post-surgical physical therapy. The raw acceleration data corresponding to a series of walking tests is firstly captured by ActiGraph accelerometers, and then used as input to theoretically estimate the peak ground reaction force (PGRF) and peak loading rate (PLR). Finally, the healing outcomes as a result of different walking speeds are predicated based on the interfragmentary movement (IFM) measured by using mechanical testing. The results show that PGRF and PLR are important factors for the callus tissue differentiation at the early stage of healing. The developed model could potentially allow the design of effective patient specific post-surgical physical therapy. [ABSTRACT FROM AUTHOR]

Mechano-regulation plays a crucial role in bone healing and involves complex cellular events. In this study, we investigate the change of mechanical microenvironment of stem cells within early fracture callus as a result of the change of fracture obliquity, gap size and fixation configuration using mechanical testing in conjunction with computational modelling. The research outcomes show that angle of obliquity ( θ ) has significant effects on interfragmentary movement (IFM) which influences mechanical microenvironment of the callus cells. Axial IFM at near cortex of fracture decreases with θ , while shear IFM significantly increases with θ . While a large θ can increase shear IFM by four-fold compared to transverse fracture, it also result in the tension–stress effect at near cortex of fracture callus. In addition, mechanical stimuli for cell differentiation within the callus are found to be strongly negatively correlated to angle of obliquity and gap size. It is also shown that a relatively flexible fixation could enhance callus formation in presence of a large gap but could lead to excessive callus strain and interstitial fluid flow when a small transverse fracture gap is present. In conclusion, there appears to be an optimal fixation configuration for a given angle of obliquity and gap size. [ABSTRACT FROM AUTHOR]

Femtosecond laser-written integrated devices involving Fresnel Zone Plates (FZPs) and waveguide arrays are demonstrated as built-in optical couplers. These structures were fabricated in borosilicate glass using a direct laser writing technique. The optical properties of these integrated photonic structures were investigated using CW lasers and high-resolution CCDs. For a single FZP coupled to a single waveguide, the overall coupling efficiency was 9%. A multiplexed optical coupler composed of three FZP layers was demonstrated to couple three waveguides simultaneously in a waveguide array. Structures of this type can be used as platforms for multichannel waveguide coupling elements or as microfluidic sensors that require higher light collecting efficiency. [ABSTRACT FROM AUTHOR]

In this article, the author responds to a comment on article "Confined propagation and near single-mode laser oscillation in a gain-guided, index antiguided optical fiber." The author discusses the work of researcher A. E. Seigman on index antiguided fibers. He further discusses various photographs reflecting the cladding circumference.

1. Bone is a remarkable living tissue that provides a framework for animal body support and motion. However, under excessive loads and deformations, bone is prone is to damage through fracture. Furthermore, once the bone is weakened by osteoporosis, bone fracture can occur even after only minimal trauma. 2. Various techniques have been developed to treat bone fractures. Successful treatment outcomes depend on a fundamental understanding of the biochemical and biomechanical environments of the fracture site. Various cell types (e.g. mesenchymal stem cells, chondrocytes, osteoblasts and osteoclasts) within the fracture site tightly control the healing process by responding to the chemical and mechanical microenvironment. However, these mechanochemical regulatory mechanisms remain poorly understood at the system level owing to the large range of variables, such as age, sex and disease-associated material properties of the tissue. 3. Computational modelling can play an important role in unravelling this complexity by combining mechanochemical interactions, revealing the dominant controlling processes and optimizing system behaviour, thereby enabling the development and evaluation of treatment strategies for individual patients. [ABSTRACT FROM AUTHOR]

Acute limb compartment syndrome (ALCS) is a surgical emergency that can have serious consequences unless promptly diagnosed and treated, which is particularly challenging when there is an unusual cause. This is a comprehensive review of reported causes of ALCS. From 1068 included articles, we found 299 discrete causes of ALCS including toxins, infections, endocrine pathology, haematological emergencies, malignancy and iatrogenic ALCS. Familiarity with this wide range of ALCS causes may assist in early diagnosis of this limb‐threatening condition. [ABSTRACT FROM AUTHOR]

Presents a letter to the editor about the association between sudden infant death syndrome and H pyroli.

Medical educators recognize the value of reflection for medical students and the role creative writing can play in fostering this. However, direct creative writing tasks can be challenging for many students, particularly those with limited experience in the arts and humanities. An alternative strategy is to utilize an indirect approach, engaging students with structured tasks that obliquely encourage reflection. This paper reports one such approach. We refer to this approach as in-verse reflection, playing on both the structure of the writing and its novel approach to reflection. Students were invited to write, in verse-like structures, about their personal and clinical experiences as medical students. Thematic analysis of their creative outputs and reactions identified four principal themes: the challenges of life as a medical student, the emotional demands of the medical course, a sense of connectedness and solidarity with fellow students, and a sense of marginality within the hospital system. Students generally found the tasks highly engaging and conducive to reflection, producing texts representing significant insights into their experiences as medical students. The reported method offers a relatively simple, structured, and guided approach to reflective writing, adding to the repertoire of methods available to educators in the medical humanities. [ABSTRACT FROM AUTHOR]

Out-of-band long wavelength emission measurements from high power, high-repetition-rate extreme-ultra-violet lithography (EUVL) laser plasma sources are imperative to estimating heat deposition in EUV mirrors, and the impact of short wavelength light transported through the imaging system to the wafer surface. This paper reports a series of experiments conducted to measure the absolute spectral irradiances of laser-plasmas produced from planar tin targets over the wavelength region of 124 to 164 nm by 1.06 μm wavelength, 10 ns full-width-at-half-maximum Gaussian laser pulses. The use of spherical targets is relevant to the EUVL source scenario. Although plasmas produced from planar surfaces evolve differently, there is a close similarity to the evolution of current from 10.6 μm CO2 laser EUVL sources, which use a pre-pulse from a lower energy solid-state laser to melt and reform an initial spherical droplet into a thin planar disc target. The maximum of radiation conversion efficiency in the 124–164 nm wavelength band (1%/2psr) occurs at the laser intensity of 1010W cm-2. A developed collisional-radiative model reveals the strong experimental spectra that originate mainly from the 4d105p2-4d105s5p, 4d105p-4d105s resonance lines, and 4d95p-4d95s unresolved transition arrays from Sn III, Sn IV, and Sn V ions, respectively. The calculated conversion efficiencies using a 2D radiation-hydrodynamics model are in agreement with the measurements. The model predicts the out-of-band (100–400 nm) radiation conversion efficiencies generated by both 1.06 and 10.6 μm pulses. The 10.6 μm laser pulse produces a higher conversion efficiency (12%/2πsr) at the lower laser intensity of 109W cm-2. [ABSTRACT FROM AUTHOR]

Flexible fixation or the so-called 'biological fixation' has been shown to encourage the formation of fracture callus, leading to better healing outcomes. However, the nature of the relationship between the degree of mechanical stability provided by a flexible fixation and the optimal healing outcomes has not been fully understood. In this study, we have developed a validated quantitative model to predict how cells in fracture callus might respond to change in their mechanical microenvironment due to different configurations of locking compression plate (LCP) in clinical practice, particularly in the early stage of healing. The model predicts that increasing flexibility of the LCP by changing the bone-plate distance (BPD) or the plate working length (WL) could enhance interfragmentary strain in the presence of a relatively large gap size (>3 mm). Furthermore, conventional LCP normally results in asymmetric tissue development during early stage of callus formation, and the increase of BPD or WL is insufficient to alleviate this problem. [ABSTRACT FROM AUTHOR]

Introduction Knowledge about the functional consequences of lower limb long bone fractures is helpful to inform patients, clinicians and employers about their recovery process and prognosis. This study aims to describe the epidemiology and health outcomes of femoral and tibial shaft fractures treated at two level I trauma centres, by comparing the differences between patients with delayed union or nonunion and patients with union. Patients and methods An analysis of registry data over two years, supplemented with medical record review, was conducted. Fracture healing was retrospectively assessed by clinical and radiological evidence of union, and the need for surgical intervention. SF-12 scores, and work and pain status were prospectively recorded at six and twelve months post injury. Results 285 fractures progressed to union and 138 fractures developed delayed union or nonunion. There was a significant difference between the two cohorts with regards to the mechanism of injury, association with multi-trauma, open fractures, grade of Gustilo classification, patient fund source, smoking status and presence of comorbidities. The SF-12 physical component score was less than 50 at both six and twelve months with improvement in the union group, but not in the delayed union or nonunion group. 72% of patients with union had returned to work at one year, but 54% continued to have pain. The difference compared to patients with delayed union or nonunion was significant. Discussion Even patients whose fractures unite in the expectant time-frame will have residual physical disability. Patients with delayed union or nonunion have still poorer outcomes, including ongoing problems with returning to work and pain. It is important to educate patients about their injury so that they have realistic expectations. This is particularly relevant given that the patients most likely to sustain femoral or tibial shaft fractures are working-age healthy adults, and up to a third of fractures may develop delayed union or nonunion. Conclusion Despite modern treatment, the patient-reported outcomes of lower limb long bone shaft fractures do not return to normal at one year. Patients with delayed union or nonunion can expect poorer outcomes. [ABSTRACT FROM AUTHOR]

The absolute spectral irradiances of laser-plasmas produced from planar zinc targets are determined over a wavelength region of 150 to 250 nm. Strong spectral radiation is generated using 60 ns full-width-at-half-maximum, 1.0 μm wavelength laser pulses with incident laser intensities as low as ~5 × 108 W cm-2. A typical radiation conversion efficiency of ~2%/2πsr is measured. Numerical calculations using a comprehensive radiation-hydrodynamics model reveal the strong experimental spectra to originate mainly from 3d94s4p-3d94s2, 3d94s4d-3d94s4p, and 3d94p-3d94s, 3d94d-3d94p unresolved-transition arrays in singly and doubly ionized zinc, respectively. [ABSTRACT FROM AUTHOR]

The purposes of this study were to determine the contributions of each shoulder muscle to glenohumeral joint force during abduction and flexion in both the anatomical and post-operative shoulder and to identify factors that may contribute to the incidence of glenoid component loosening/failure and joint instability in the shoulder after reverse shoulder arthroplasty (RSA). Eight cadaveric upper extremities were mounted onto a testing apparatus. Muscle lines of action were measured, and muscle forces and muscle contributions to glenohumeral joint forces were determined during abduction and flexion of the pre-operative anatomical shoulder and of the shoulder after arthroplasty. Muscle forces in the middle deltoid during abduction and those in the middle and anterior deltoid during flexion were significantly lower in the reverse shoulder than the pre-operative shoulder ( p < 0.017). The resultant glenohumeral joint force in the reverse shoulder was significantly lower than that in the pre-operative shoulder; however, the superior shear force acting at the glenohumeral joint was significantly higher ( p < 0.001). Reverse total shoulder arthroplasty reduces muscle effort in performing lifting and pushing tasks; however, reduced joint compressive force has the potential to compromise joint stability, while an increased superior joint shear force may contribute to component loosening/failure. Because greater superior shear force is generated in flexion than in abduction, care should be taken to avoid excessive shoulder loading in this plane of elevation. © 2011 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 29:1850-1858, 2011 [ABSTRACT FROM AUTHOR]

A new Laser-Induced Breakdown Spectroscopy (LIBS) enhancement method utilizing interaction between microwave radiation and laser-induced plasma has been evaluated. Experimental parameters such as laser pulse irradiance, microwave duration, and surrounding gas were studied and optimized for the microwave effect through a series of experiments on a piece of alumina ceramic sample. Up to 33 times enhancement on different spectral lines was achieved. Enhancement of the line intensity was found to be at a maximum when the laser ablation was induced at low irradiance on a large area in normal atmosphere. The enhancement was element-dependent and stronger for transitions with low excitation energy. The microwave enhancement in argon atmosphere was not as effective as in air, and the reasons are discussed. [ABSTRACT FROM AUTHOR]