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The recent trends in material science are focused toward composite materials. It has been used in a lot of real-life applications. In composite material, recently researchers concentrated on the natural fibers because of their sustainable effect and focus on the environment. In this paper, sunnhemp and flax natural fibers were selected for making the new hybrid natural composite material. The mechanical properties of hybrid natural composites were determined by experimental approach. The hybrid composite plates were made with the blending of sunnhemp and flax fibers using polyester resin as a matrix material. The sunnhemp-flax reinforced polyester composite plates were made by various fiber lengths such as 15 mm, 30 mm, and 50 mm. Similarly, composite plates were made with different orientations angles like 0°, 45°, and 90°. The mechanical test has been conducted for different orientations such as unidirectional, biaxial, triaxial, and random. It was found that the triaxial-oriented fiber exhibited better results in tensile strength (86.3 MPa), flexural strength (117.1 MPa), and impact strength (153.8 kJ/m2).

Background The current study aimed at observing the cyto morphological patterns in patients presenting with enlarged cervical lymph nodes, Delineate distribution of clinical diagnosis and to correlate them with fine needle aspiration cytology (FNAC), their distribution with age and gender specific distribution of various cytomorphological patterns of cervical lymphadenopathy. Materials and Methods Totally 60 consecutive patients presenting with cervical lymphadenopathy from September 2021 to August 2022, in the Department of ENT, Government Vellore Medical College, Vellore, Tamil Nadu, India, were enrolled into the current study. All patients >12 years of either sex who presented with cervical lymph node enlargement, following the exclusion of all cases where, <12 years of age, FNAC smears were inadequate or suboptimal for diagnostic interpretation. Based on clinical findings they are divided into 3 groups: Non specific, tubercular, neoplastic lymphadenitis. The clinical diagnosis was then correlated with FNAC diagnosis. Results Maximum number of cases (75%) presented with neck swelling of less than 3 months duration. The majority of the cases (98%) Presented with unilateral neck swelling. The majority of our patients (27%) Presented with level II neck nodes. In the majority of our patients the size of lymph nodes was less than 3 cms. Consistency of lymph nodes varied from soft to firm in about 46 patients . 10 Patients had hard neck nodes. In 45(80%) patients in our study had clinically mobile lymph nodes and there was fixity of lymph nodes in 11(20%) patients. In our study out of 45 patients who presented with mobile lymph nodes, 38 were discrete while 7 patients presented with matted lymph nodes. We made a clinical diagnosis of nonspecific cervical lymphadenopathy in 23 patients (41%), Tubercular lymphadenitis in 22 patients (39%),Neoplastic nodes in 11 patients (20%) Conclusion Cervical lymphadenopathy is a common occurrence and should be duly noted and a systemic approach should be followed to diagnose the cause which further helps in determining the proper treatment course for the patient. Mostly history and physical examination reveal the etiology for the same and hence should be taken into consideration while examining. When the cause of lymphadenopathy remains unexplained,a three to four weeks of observation period is appropriate when the clinical setting indicates high probability of benign disease. Thus a case of cervical lymphadenopathy has to be evaluated carefully to prevent any misdiagnosis. [ABSTRACT FROM AUTHOR]

The objective of this work is to investigate the effect of graphite addition to Al/SiC composites manufactured by stir casting process. The reinforcement content of graphite was varied from 2.5 wt. % to 7.5 wt. %, for preparing three types of hybrid composites. Al/SiC/Gr hybrid composites prepared by stir casting method have uniform dispersion of SiC and Gr particle reinforcement. High-speed machining of Al/SiC/Gr was done in CNC machine using PCD insert at a cutting speed of 300, 400 and 500 m/min. From ANOVA analysis, cutting speed (48.76%) is the critical factor affecting surface roughness. Grey Relational analysis was done for simultaneous improvement of Material Removal Rate and surface roughness. Roughness values were predicted using Taguchi method and predicted values were compared with experimental results. Elemental chips produced during machining leads to reduced roughness values. [ABSTRACT FROM AUTHOR]

The current study uses an economical and eco friendly method to produce gold (Au) nanoparticles (NPs) using Polygala elongata leaf (PEL) extract as a reducing and stabilizing agent. The synthesized materials were characterized using a range of methods, including as BET analysis, TEM-SAED, FT-IR, UV–Vis, and XRD. Biogenic AuNPs' spherical form was shown by SEM and TEM investigations, which also showed that the particles' size range was 10–20 nm, their distribution was homogeneous, and there observed minimal aggregation. The production of biogenic AuNPs was confirmed by the observation of a surface plasmon resonance peak in the absorption spectra, which was detected at 540 nm. Additionally, studies were conducted on the catalytic, cytotoxic, antioxidant, and anticancer characteristics of biogenic AuNPs. The biogenic AuNPs exhibited adaptable applications as a heterogeneous catalyst, achieving percentage degradations of 73 % and 88 % under UV light irradiation, particularly in catalyzing the reduction of Methylene Blue (MeB). Furthermore, the antioxidant properties were evaluated using DPPH free radical scavenging assay in regarding rutin, a widely used antioxidant. With a cytotoxicity value of 500 µg/ml, the produced AuNPs had a strong dose-dependent inhibitory effect on the development of the lung cancer cell line (A549). Therefore, biogenic AuNPs hold potential applications across various research domains, spanning biological and industrial sectors, as well as in the removal of harmful contaminants in water purification.

Static random-access memory (SRAM) is the most prevalent type of memory used in current system-on-chips (SOC). SRAMs built using Complementary metal oxide semiconductor (CMOS) transistors, suffer from low stability and significant power dissipation at nano scale regime [1]. Studies show that the Carbon nanotube field effect transistor (CNTFET) are prominent to use at nano scale region. This article proposes a 12T CNTFET SRAM cell and its performance metrics like power, stability and delay are compared with various other recent SRAM cells by simulating them using CNTFETs. Two Schmitt trigger (ST) based cross coupled inverter arrangement make up the storage cell in the suggested 12T CNTFET SRAM bit cell. ST-based inverter has stacked N-type transistors, which reduces the circuit's leakage and the voltage transfer characteristics (VTC) of ST inverter is also sharper than the other conventional inverters, thereby enhancing the stability performance of the proposed bit cell. The cell also uses feedback cutting transistor and a separate read and write path to further improve the stability performances during read and write modes. The suggested 12T CNTFET SRAM cell shows higher write SNM, hold SNM and read SNM when compared to other state of the art SRAM cells. The read and write delay of the proposed 12T CNTFET SRAM cell is also seen to improve in contrast to the other SRAM designs. The proposed 12T CNTFET SRAM cell when simulated using 32 nm CNTFET at 0.9 V, shows write power, hold power, read power, write delay, read delay, write static noise margin (WSNM), HSNM and read static noise margin (RSNM), as 0.19 nW, 1.61 nW, 3.13 µW, 119 pS, 7.33 pS, 444 mV, 420 mV, 420 mV respectively. The suggested cell is also tested for parametric variations and its performance is also recorded. The proposed cell surpasses all other cells considered as far as power and stability are concerned making it suitable for usage in smart devices like smart bands, smart watches etc. A 32 nm Stanford University model is used to simulate the proposed 12T CNTFET SRAM cell using the HSPICE tool.

Barnyard millet is one of the hardiest, climate resilient and fast growing crop that is bestowed with high nutrient content in grains. An experiment was carried out in barnyard millet under natural sodic soil condition to study the genetic variability and association for different morphological and yield contributing traits. Ninety nine barnyard millet genotypes including two commercial check varieties viz., MDU1 and CO (KV) 2 were evaluated under sodic soil condition. Analysis of variance revealed significant variation for all the characters studied. High phenotypic coefficient of variation, genotypic coefficient of variation and heritability were recorded for plant height, ear width, lower raceme length, flag leaf length, flag leaf width and grain yield per plant. Association studies indicated that grain yield per plant had highly significant positive correlation with days to fifty percent flowering, days to maturity, ear width and thousand grain weight. Path coefficient analysis indicated that the highest direct and indirect effect on grain yield per plant was exhibited by days to fifty percent flowering. Thus, days to fifty percent flowering, days to maturity, ear width and thousand grain weight can be used as selection indices for increasing grain yield of barnyard millet in sodic soil.

The present study was carried out during kharif 2018 at Anbil Dharmalingam Agricultural College and Research Institute, Trichy under sodic field condition. The experimental material comprising of 120 finger millet genotypes along with two checks viz., TRY 1and Paiyur 2 was laid out in randomized complete block design. Observations were recorded for 13 quantitative characters and the data were analyzed for biometric characters viz., phenotypic coefficient of variation (PCV), genotypic coefficient of variation (GCV), heritability(h2) and genetic advance as per cent of mean (GAM).High PCV and GCV were recorded for the characters Na+/K+ ratio, grain yield per plant, number of tillers per plant, number of productive tillers per plant and straw yield per plant indicating the presence of high variability among the finger millet genotypes. High heritability coupled with genetic advance as per cent of mean was observed for all the characters except days to maturity it may be due to additive effects and selection may be effective for those character with high heritability and genetic advance viz., days to 50% flowering, plant height, earhead length, finger length, number of fingers per earhead, number of tillers per plant, number of productive tillers per plant, 1000 grain weigh, Na+/K+ ratio, straw yield per plant and grain yield per plant.

The structural motifs responsible for the formation of bowls, balls and sheets of orthoboric acid were pointed out in an earlier publication (Elango et al. J. Phys. Chem. A2005, 109, 8587). It is shown in the present study that metaboric acid forms similar bowls, balls and sheets, despite the fact that the basic unit for cluster formation is different. [ABSTRACT FROM AUTHOR]

Cardinality guided molecular tailoring approach (CG-MTA) [Ganesh et al. J. Chem. Phys.2006, 125, 104019] has been effectively employed to perform ab initio calculations for large molecular clusters of boric acid. It is evident from the results that boric acid forms nanotubes, structurally similar to carbon nanotubes, with the help of an extensive hydrogen-bonding (H-bonding) network. Planar rosette-shaped hexamer of boric acid is the smallest repeating unit in such nanotubes. The stability of these tubes increases due to enhancement in the number of H-bonding interactions as the diameter increases. An analysis of molecular electrostatic potential (MESP) of these systems provides interesting features regarding the reactivity of these tubes. It is predicted that due to alternate negative and positive potentials on O and B atoms, respectively, boric acid nanotubes will interact favorably with polar systems such as water and can also form multiwalled tubes. [ABSTRACT FROM AUTHOR]

Hartree−Fock (HF) calculations using 6-31G*, 6-311++G(d,p), aug-cc-pVDZ, and aug-cc-pVTZ basis sets show that hydrogen peroxide molecular clusters tend to form hydrogen-bonded cyclic and cage structures along the lines expected of a molecule which can act as a proton donor as well as an acceptor. These results are reiterated by density functional theoretic (DFT) calculations with B3LYP parametrization and also by second-order Møller−Plesset perturbation (MP2) theory using 6-31G* and 6-311++G(d,p) basis sets. Trends in stabilization energies and geometrical parameters obtained at the HF level using 6-311++G(d,p), aug-cc-pVDZ, and aug-cc-pVTZ basis sets are similar to those obtained from HF/6-31G* calculation. In addition, the HF calculations suggest the formation of stable helical structures for larger clusters, provided the neighbors form an open book structure. [ABSTRACT FROM AUTHOR]

Thermal 6π electrocyclization of cyclononatetraene (CNT), its hetero-substituted analogues, and its benzannelated derivatives have been investigated by using the B3LYP method employing 6-31G* and 6-311+G** basis sets. The results indicate that heterosubstitution and benzannelation influence the rate of cyclization. Nucleus independent chemical shifts (NICS), conceptual density functional theory (DFT) based reactivity descriptors, group electronegativity values, and barriers to planarity provide complementary evidence for the predicted rate of cyclization. The available experimental data are in good agreement with the computed values. [ABSTRACT FROM AUTHOR]

Sorghum is a staple food in the arid and semi-arid tropics, and is an important animal and bird feed in some developed countries. Very limited reports are available on anti-nutritional factors in sorghum. Grains of 200 sorghum genotypes including adapted cultivars and parental lines were characterized for the levels of cyanogens and trypsin inhibitor. Significant variation was observed for cyanogens (14.2-173.6 ppm) and trypsin inhibitor (1.6-12.8 TIU). The popular cultivars and parental lines had only moderate levels of these anti-nutritional factors. Selected 33 genotypes including the ones with extreme values were reanalyzed and the results were confirmed with high correlation for cyanogens (r = 0.96, p < 0.001), while in case of trypsin inhibitor a moderate correlation (r = 0.41, p = 0.04) was obtained. The results show that presence of cyanogens and trypsin inhibitors in sorghum do not pose a serious challenge to the nutritional quality as perceived previously in the developed world.

Pumps are widely used in a variety of applications. Defects and breakdown of these pumps will result in significant economic loss. Therefore, these must be under continuous observation. In various applications, the role of pump is decisive and condition monitoring is crucial. A completely automated on-line pump condition monitoring system which can automatically inform the operator of any faults, promising reduction in maintenance cost with a greater productivity saving both time and money.This paper presents the application of support vector machine for classification using statistical features extracted from vibration signals under good and faulty conditions of a pump. Effectiveness of various kernel functions of C-SVC and -SVC models are compared. The study gives some empirical guidelines for selecting an appropriate kernel in a classification problem.

Bearing fault, Impeller fault, seal fault and cavitation are the main causes of breakdown in a mono block centrifugal pump and hence, the detection and diagnosis of these mechanical faults in a mono block centrifugal pump is very crucial for its reliable operation. Based on a continuous acquisition of signals with a data acquisition system, it is possible to classify the faults. This is achieved by the extraction of features from the measured data and employing data mining approaches to explore the structural information hidden in the signals acquired. In the present study, statistical features derived from the vibration data are used as the features. In order to increase the robustness of the classifier and to reduce the data processing load, dimensionality reduction is necessary. In this paper dimensionality reduction is performed using traditional dimensionality reduction techniques and nonlinear dimensionality reduction techniques. The effectiveness of each dimensionality reduction technique is also verified using visual analysis. The reduced feature set is then classified using a decision tree. The results obtained are compared with those generated by classifiers such as Naïve Bayes, Bayes Net and kNN. The effort is to bring out the better dimensionality reduction technique–classifier combination.

Due to the rise in vehicular emissions, the rapid deterioration of the atmospheric air quality is a cause for concern in a global scale. In this context, the objective of this study is to explore the effect of post-injection parameters on a continuous active regeneration trap (CART) to mitigate harmful greenhouse gases (GHG) and particulate smoke emissions (PSE) using diesel fuel reformulated by long-chain microalgae bio-alcohol and low-density microalgae biodiesel. Furthermore, the efficiency of the CART unit is analyzed based on its ability to mitigate the harmful emissions without sacrificing the engine performance characteristics. From the study, it was observed that the maximum de-smoke efficiency of 67.85% is observed at a post-injection timing (PIT) of 20°CA aTDC at a post-injection mass (PIM) of 4 mg for low load condition while operating on microalgae biodiesel. While operating on microalgae bio-alcohol, the maximum de-smoke CART efficiency was observed as 67.25% and 55.78% for low and medium load conditions at a PIT and PIM of 20°CA aTDC and 2 mg while operating on the microalgae bio-alcohol. Likewise, the maximum de-HC CART efficiency was obtained at a PIT and PIM of 10°CA aTDC and 1 mg with a reduction of about 75% and 73.8% for medium and high load conditions. A slight reduction in oxides of nitrogen with the complete elimination of carbon monoxide emissions is observed after CART treatment for both the fuels., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Competing Interests: Competing interests: None.

Background: Medical and surgical fields continue to be marred by gender disparities. The "leaky pipeline" effect, representing a gradual decline in female representation along the academic ladder, has been well documented in plastic surgery. However, gender differences in abstract presentation at national plastic surgery meetings and subsequent publications remains elusive., Methods: We reviewed abstracts presented at the 2014 and 2015 annual meetings of the American Association of Plastic Surgeons (AAPS); American Society of Plastic Surgeons (ASPS), and the Plastic Surgery Research Council (PSRC). Several abstract characteristics including the names of the first and last authors were extracted. Genderize.io and Google search were used to identify the authors' gender., Results: We identified 1174 abstracts presented at the three identified meetings. Females comprised 29% of the presenters and 16% of abstract senior authors (ASAs). No gender differences were identified between the meetings, type of presentation (oral versus poster), and year of presentation. The only difference was in the subspecialty of the abstracts. Successful conversion to full-text articles was similar for male and female presenters (68% versus 62%, P = 0.065) but higher for male ASAs (68% versus 59%, P = 0.01). When an author change occurred, female presenters and ASAs were more likely to be replaced by males (P < 0.001)., Conclusion: Gender differences continue to be evident in academic plastic surgery with women constituting a minority of both presenters and senior authors on abstracts presented at national plastic surgery meetings. Future work should assess whether flexible and supportive work policies can foster greater female representation in academic plastic surgery., Competing Interests: Conflict of interest/funding acknowledgment All authors have no conflicts of interest or financial disclosures with regards to the content of the article., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The foundation programme is a 2-year training programme for newly qualified doctors and aims to bridge the gap between medical school and specialty training. The pandemic led to some major disruptions to foundation training. As foundation trainees, we encountered new challenges: there were reduced learning opportunities and our future paths became uncertain with changes to specialty training applications and membership exams. However, it is said that every crisis creates new opportunities and is a test of our resilience and innovativeness. There was the adoption of novel teaching methods, new research opportunities, increased importance given to teamwork and support for our wellbeing and mental health. We learnt lessons from this crisis that we should take forward to improve foundation training for the future., (© Royal College of Physicians 2021. All rights reserved.)

Patients with end-stage kidney disease (ESKD) have a high prevalence of cardiovascular disease; it is the leading cause of death in these patients and the optimisation of their cardiovascular health may improve their post-transplant outcomes. Patients awaiting renal transplant often spend significant amounts of time on the waiting list allowing for the assessment and optimisation of their cardiovascular system. Coronary artery disease (CAD) is commonly seen in these patients and we explore the possible functional and anatomical investigations that can help assess and manage CAD in renal transplant candidates. We also discuss other aspects of cardiovascular assessment and management including arrhythmias, impaired ventricular function, valvular disease, lifestyle and pulmonary arterial hypertension. We hope that this review can form a basis for centres hoping to implement an enhanced recovery after surgery (ERAS) protocol for renal transplantation.

Enhanced recovery after surgery (ERAS) initially started in the early 2000s as a series of protocols to improve the perioperative care of surgical patients. They aimed to increase patient satisfaction while reducing postoperative complications and postoperative length of stay. Despite these protocols being widely adopted in many fields of surgery, they are yet to be adopted in pancreatic transplantation: a high-risk surgery with often prolonged length of postoperative stay and high rate of complications. We have analysed the literature in pancreatic and transplantation surgery to identify the necessary preoperative, intra-operative and postoperative components of an ERAS pathway in pancreas transplantation.

Development of photo detectors based on different semiconducting materials with high performance has been in progress in recent past, however, there is a lot of difficulties in developing the more effective photo detectors-based devices with high responsivity, detectivity and quantum efficiency. Hence, we have synthesized pure CuS and CuO@CuS core-shell heterostructure based photo detectors with high performance by simple and cost-effective two-step chemical co-precipitation method. The phase purity of CuS and CuO@CuS composite was observed by XRD analysis and the result were verified with Raman spectroscopy studies. Sphere like morphology of pure CuS and core-shell structure formation of CuO@CuS are observed with scanning and transmission electron microscopes. The presence of expected elements has been confirmed with EDX elemental mapping. Light harvesting photodiodes were fabricated by using n-type silicon substrate through drop cost method. Photo sensitive parameters of fabricated diodes were analyzed by I-V characteristics. The p-CuO@CuS (1:1)/n-Si diode owned a maximum photosensitivity (Ps) ∼ 7.76 × 10 4 %, photoresponsivity (R) ∼ 798.61 mA/W, external quantum efficiency ( E Q E )∼309.66 % and specific detectivity (D*) ∼ 8.19 × 10 11 Jones when compared to p-CuS/n-Si diode. The obtained results revealed that the core/shell heterostructure of CuO@CuS is the most appropriate for photo detection., Competing Interests: Authors declares that there is no conflict of interest in current article., (© 2020 Elsevier B.V. All rights reserved.)

Toll-like receptors (TLR) trigger the immune system to mount a rapid innate response capable of protecting the host from a wide variety of bacterial and viral pathogens. There is interest in harnessing TLR agonists to reduce the susceptibility of at-risk populations to infection. However, the widespread prophylactic use of TLR agonists has been compromised by the need to administer them by parenteral injection. An exception is the TLR7/8 agonist R848, which can boost gastrointestinal and systemic immunity when administered orally. This work examines the effect of R848 on host susceptibility to Listeria monocytogenes in a murine challenge model and describes the underlying mechanisms. Results show that prophylactic administration of R848 significantly reduces susceptibility to infection of BALB/c mice, an effect that lasts 1 week. Oral R848 directly stimulated B cells to produce cytokines and Ig. In the absence of B cells, R848-mediated protection was lost. These findings support the use of oral R848 to reduce the susceptibility of at-risk individuals to infection and identify the critical role of B cells in TLR7-mediated resistance to bacterial infection., (This is a work of the U.S. Government and is not subject to copyright protection in the United States. Foreign copyrights may apply.)

Elimination of HIV-1 requires clearance and removal of integrated proviral DNA from infected cells and tissues. Here, sequential long-acting slow-effective release antiviral therapy (LASER ART) and CRISPR-Cas9 demonstrate viral clearance in latent infectious reservoirs in HIV-1 infected humanized mice. HIV-1 subgenomic DNA fragments, spanning the long terminal repeats and the Gag gene, are excised in vivo, resulting in elimination of integrated proviral DNA; virus is not detected in blood, lymphoid tissue, bone marrow and brain by nested and digital-droplet PCR as well as RNAscope tests. No CRISPR-Cas9 mediated off-target effects are detected. Adoptive transfer of human immunocytes from dual treated, virus-free animals to uninfected humanized mice fails to produce infectious progeny virus. In contrast, HIV-1 is readily detected following sole LASER ART or CRISPR-Cas9 treatment. These data provide proof-of-concept that permanent viral elimination is possible.

Purpose of Review: Donor-recipient human leukocyte antigen (HLA) matching improves outcomes after solid-organ transplantation, but current assessment of HLA incompatibility is inadequate as it does not consider the relative immunogenicity of individual HLA mismatches. In this article, we review existing strategies for assessing HLA immunogenicity and discuss current challenges and future opportunities in this field., Recent Findings: Current HLA immunogenicity algorithms focus primarily on the humoral component of the alloimmune response and aim to determine a measure of 'dissimilarity' between donor and recipient HLA. This can be achieved by deriving information from comparison of donor and recipient HLA at the amino acid sequence, structural and/or the physicochemical level, accounting for both B-cell and T-cell pathways of alloreactivity. Substantial evidence now supports the superiority of this molecular definition of HLA incompatibility, over conventional enumeration of HLA antigenic differences, for assessing the risk of humoral alloimmunity and for predicting graft outcomes after transplantation., Summary: Significant progress has been made in developing computational HLA immunogenicity algorithms that offer exciting opportunities for a more rational approach to determining the degree of donor-recipient HLA incompatibility and to defining HLA-related immunological risk. A number of challenges now need to be overcome to enable their implementation into clinical practice.

Bacterial biofilms display a collective lifestyle, wherein the cells secrete extracellular polymeric substances (EPS) that helps in adhesion, aggregation, stability, and to protect the bacteria from antimicrobials. We asked whether the EPS could act as a public good for the biofilm and observed that infiltration of cells that do not produce matrix components weakened the biofilm of Salmonella enterica serovar Typhimurium. EPS production was costly for the producing cells, as indicated by a significant reduction in the fitness of wild type (WT) cells during competitive planktonic growth relative to the non-producers. Infiltration frequency of non-producers in the biofilm showed a concomitant decrease in overall productivity. It was apparent in the confocal images that the non-producing cells benefit from the EPS produced by the Wild Type (WT) to stay in the biofilm. The biofilm containing non-producing cells were more significantly susceptible to sodium hypochlorite and ciprofloxacin treatment than the WT biofilm. Biofilm infiltrated with non-producers delayed the pathogenesis, as tested in a murine model. The cell types were spatially assorted, with non-producers being edged out in the biofilm. However, cellulose was found to act as a barrier to keep the non-producers away from the WT microcolony. Our results show that the infiltration of non-cooperating cell types can substantially weaken the biofilm making it vulnerable to antibacterials and delay their pathogenesis. Cellulose, a component of EPS, was shown to play a pivotal role of acting as the main public good, and to edge-out the non-producers away from the cooperating microcolony.

Many bacteria secrete a highly hydrated framework of extracellular polymer matrix on suitable substrates and embed within the matrix to form a biofilm. Bacterial biofilms are observed on many medical devices, endocarditis, periodontitis and lung infections in cystic fibrosis patients. Bacteria in biofilm are protected from antibiotics and >1,000 times of the minimum inhibitory concentration may be required to treat biofilm infections. Here, we demonstrated that shock waves could be used to remove Salmonella, Pseudomonas and Staphylococcus biofilms in urinary catheters. The studies were extended to a Pseudomonas chronic pneumonia lung infection and Staphylococcus skin suture infection model in mice. The biofilm infections in mice, treated with shock waves became susceptible to antibiotics, unlike untreated biofilms. Mice exposed to shock waves responded to ciprofloxacin treatment, while ciprofloxacin alone was ineffective in treating the infection. These results demonstrate for the first time that, shock waves, combined with antibiotic treatment can be used to treat biofilm infection on medical devices as well as in situ infections.

Bacterial biofilms are associated with 80-90% of infections. Within the biofilm, bacteria are refractile to antibiotics, requiring concentrations >1,000 times the minimum inhibitory concentration. Proteins, carbohydrates and DNA are the major components of biofilm matrix. Pseudomonas aeruginosa (PA) biofilms, which are majorly associated with chronic lung infection, contain extracellular DNA (eDNA) as a major component. Herein, we report for the first time that L-Methionine (L-Met) at 0.5 μM inhibits Pseudomonas aeruginosa (PA) biofilm formation and disassembles established PA biofilm by inducing DNase expression. Four DNase genes (sbcB, endA, eddB and recJ) were highly up-regulated upon L-Met treatment along with increased DNase activity in the culture supernatant. Since eDNA plays a major role in establishing and maintaining the PA biofilm, DNase activity is effective in disrupting the biofilm. Upon treatment with L-Met, the otherwise recalcitrant PA biofilm now shows susceptibility to ciprofloxacin. This was reflected in vivo, in the murine chronic PA lung infection model. Mice treated with L-Met responded better to antibiotic treatment, leading to enhanced survival as compared to mice treated with ciprofloxacin alone. These results clearly demonstrate that L-Met can be used along with antibiotic as an effective therapeutic against chronic PA biofilm infection.

Objectives: The ability to target conventional drugs efficiently inside cells to kill intraphagosomal bacteria has been a major hurdle in treatment of infective diseases. We aimed to develop an efficient drug delivery system for combating infection caused by Salmonella, a well-known intracellular and intraphagosomal pathogen. Chitosan-dextran sulphate (CD) nanocapsules were assessed for their efficiency in delivering drugs against Salmonella., Methods: The CD nanocapsules were prepared using the layer-by-layer method and loaded with ciprofloxacin or ceftriaxone. Antibiotic-loaded nanocapsules were analysed in vitro for their ability to enter epithelial and macrophage cells to kill Salmonella. In vivo pharmacokinetics and organ distribution studies were performed to check the efficiency of the delivery system. The in vivo antibacterial activity of free antibiotic and antibiotic loaded into nanocapsules was tested in a murine salmonellosis model., Results: In vitro and in vivo experiments showed that this delivery system can be used effectively to clear Salmonella infection. CD nanocapsules were successfully employed for efficient targeting and killing of the intracellular pathogen at a dosage significantly lower than that of the free antibiotic. The increased retention time of ciprofloxacin in the blood and organs when it was delivered by CD nanocapsules compared with the conventional routes of administration may be the reason underlying the requirement for a reduced dosage and frequency of antibiotic administration., Conclusions: CD nanocapsules can be used as an efficient drug delivery system to treat intraphagosomal pathogens, especially Salmonella infection. This delivery system might be used effectively for other vacuolar pathogens including Mycobacteria, Brucella and Legionella.

The structure and stability of quasi one-dimensional (1D) ice nanotubes (INTs) have been investigated using Density Functional Theory (DFT) based Becke's three parameter Lee-Yang-Parr exchange and correlation functional (B3LYP) method employing various basis sets. Four different INTs, namely, (4,0)-INT, (5,0)-INT, (6,0)-INT, and (8,0)-INT with different lengths have been considered in this study. The calculated stabilization energies (SEs) illustrate that the stability of INT is proportional to its length and diameter. Further, the encapsulation of various gas molecules (CO(2), N(2)O, CO, N(2), and H(2)) inside the INTs has also been investigated. The calculated SEs of different endohedral complexes reveal that all these gas molecules are stable inside the tubes. The Bader's theory of atoms in molecule (AIM) has been used to characterize intra- and inter-ring H-bonding interactions. The electron density topological parameters derived from AIM theory brings out the difference between the intra- and inter-ring H-bonds of INTs.

Electronic structure calculations were carried out to study the various isomers of formula C(3)H(6)O, as a part of our current quantum chemical and dynamical approaches to intra- and intermolecular kinetics for the C(n)H(2n)O (n = 1, 2, 3) molecules. The usefulness of the GRRM (global reaction route mapping) program developed by Ohno and Maeda in predicting the structure of all isomers and of the transition states connecting them is fully exploited. All the isomers are identified as local minima on the MP2/CC-PVDZ potential energy surface. Acetone is the most stable isomer. In increasing order of stability the others are propanal, 2-propenol, 1-propenol, allyl alcohol, methyl vinyl ether, cyclopropanol, propylene oxide, and oxetane. Various isomerization paths connecting them are identified. All the transition states are fully characterized using intrinsic reaction coordinate calculations. The isomerization reactions may proceed through a single step or involve an intermediate species which is either a carbene or a diradical. Special attention is devoted to propylene oxide, a favorite molecule in current photochemical and stereodynamical studies because of its chiral nature. It is a rigid molecule, and chirality switching is found to be supported by its isomers. Two different chirality switching mechanisms which are assisted by propanal and allyl alcohol are presented.

Various isomers of the trigonal dianion metal clusters, X(3)(2-), X = Be, Mg, Ca, and their mono- and disodium complexes are optimized at the B3LYP/6-311+G(d) level. Different conceptual density functional theory based reactivity descriptors as well as the induced magnetic field values are calculated to understand the stability and aromaticity of these systems. Possibility of bond stretch isomerism is explored. Genetic algorithm results lend additional insights into the structures of these isomers., (Copyright 2009 Wiley Periodicals, Inc.)

The interaction between the fragment of carbon nanotube (CNT) and carbohydrates has been investigated using MP2 and M05-2X methods using various basis sets in gas phase. Three carbohydrates, viz., beta-d-glucose, beta-d-galactose, and beta-d-xylose with different degree of hydrophobic nature have been selected for this investigation. With a view to assess the effect of curvature on the interaction between the carbohydrates and CNT, calculations on intermolecular complexes comprising of coronene (COR) and carbohydrates have also been carried out in gas phase. Results obtained from electronic structure calculations combined with the Bader's electron density analysis reveal that CH...pi interaction is the predominant one in the stabilization of the carbohydrate-CNT and carbohydrate-COR complexes. Furthermore, the importance of OH...pi and lone pair...pi (lp...pi) interactions are also evident from the results. The calculated BEs for the various carbohydrate-CNT and carbohydrate-COR complexes at M05-2X with dual basis set [aug-cc-pVTZ for carbohydrate + cc-pVTZ for both CNT and COR] vary from -2.52 to -5.14 and from -4.14 to -8.04 kcal/mol, respectively. The corresponding BEs obtained from MP2/6-311++G(d,p)//M05-2X/6-31+G(d,p) level of calculation range from -4.92 to -9.93 and from -6.75 to -12.53 kcal/mol. Close scrutiny of the energetics of all the complexes elucidate that the electron correlation energy (dispersion energy) significantly contribute to the stability of these complexes. It is found from the analysis of geometrical parameters and BEs that the interplay of orientation of the X-H (X = C and O) bond to the pi-surface is crucial for the recognition and further stabilization. Molecular electrostatic potential (MESP) isosurfaces of curved and planar surfaces have clearly provided the difference between the pi-electron distributions. Evidences form the energy decomposition analysis elicit that the dispersive interaction plays a significant role in the overall stabilization of the complexes. And, it is possible to observe the delicate balance between the electrostatic interaction and the exchange-repulsion energy.

The structure and stability of linear (helical) water chains (H2O)n, n = 5-20 as obtained from ab initio/DFT calculations are reported along with an atoms-in-molecules (AIM) analysis of hydrogen bond critical points and their characteristics. The resulting helical chain arrangement is one of the predominant motifs in different host environments; although they may not be the most stable, it is shown that these linear water chain clusters could exist in their own right.

The structural motifs responsible for the formation of bowls, balls and sheets of orthoboric acid were pointed out in an earlier publication (Elango et al. J. Phys. Chem. A 2005, 109, 8587). It is shown in the present study that metaboric acid forms similar bowls, balls and sheets, despite the fact that the basic unit for cluster formation is different.

Cardinality guided molecular tailoring approach (CG-MTA) [Ganesh et al. J. Chem. Phys. 2006, 125, 104019] has been effectively employed to perform ab initio calculations for large molecular clusters of boric acid. It is evident from the results that boric acid forms nanotubes, structurally similar to carbon nanotubes, with the help of an extensive hydrogen-bonding (H-bonding) network. Planar rosette-shaped hexamer of boric acid is the smallest repeating unit in such nanotubes. The stability of these tubes increases due to enhancement in the number of H-bonding interactions as the diameter increases. An analysis of molecular electrostatic potential (MESP) of these systems provides interesting features regarding the reactivity of these tubes. It is predicted that due to alternate negative and positive potentials on O and B atoms, respectively, boric acid nanotubes will interact favorably with polar systems such as water and can also form multiwalled tubes.

The fundamental principles of pericyclic reactions are governed by the Woodward-Hoffmann rules, which state that these reactions can only take place if the symmetries of the reactants' molecular orbitals and the products' molecular orbitals are the same. As such, these rules rely on the nodal structure of either the wave function or the frontier molecular orbitals, so it is unclear how these rules can be recovered in the density functional reactivity theory (or "conceptual DFT"), where the basic quantity is the strictly positive electron density. A third, nonsymmetry based approach to predict the outcome of pericyclic reactions is due to Zimmerman which uses the concept of the aromatic transition states: allowed reactions possess aromatic transition states, while forbidden reactions possess antiaromatic transition states. Based on our recent work on cycloadditions, we investigate the initial response of the chemical hardness, a central DFT based reactivity index, along the reaction profiles of a series of electrocyclizations. For a number of cases, we also compute complete initial reaction coordinate (IRC) paths and hardness profiles. We find that the hardness response is always higher for the allowed modes than for the forbidden modes. This suggests that the initial hardness response along the IRC is the key for casting the Woodward-Hoffmann rules into conceptual DFT.

Thermal and microwave assisted [4+2] cycloadditions of 1,4-diaryl-1-aza-1,3-butadienes with allenic esters lead to cycloadducts, which after a 1,3-H shift afford variedly substituted unsymmetrical 2-alkyl-1,4-diaryl-3-ethoxycarbonyl-1,4-dihydropyridines in high yields. Reactions carried out under microwave irradiation are cleaner and give higher yields with much shortened reaction times. Density functional theory (DFT) at the B3LYP/6-31G* level has been used to calculate geometric features of the reactants, barrier for s-trans to s-cis and reverse isomerization of azadienes (5a-d, 10a-e), dihedral angles between N(1), C(2), C(3), and C(4) atoms of azadienes along with various indices such as chemical hardness (eta), chemical potential (micro), global electrophilicity (omega), and the difference in global electrophilicity (Deltaomega) between the reacting pairs and Fukui functions (f (+) and f(-)). The results revealed that s-trans is the predominant conformation of azadienes at ambient temperature and the barrier for conversion of the s-trans rotamer of 1-azadienes to s-cis may be the major factor influencing the chemoselectivity, i.e., [4+2] verses [2+2] cycloaddition. The regiochemistry of the observed cycloadditions is collated with the obtained local electrophilicity indices (Fukui functions). Transition states for the formation of both [4+2] and [2+2] cycloadducts as located at the PM3 level indicate that the transition state for the formation of [4+2] cycloadducts has lower energy, again supporting the earlier conclusion that preferred formation of [4+2] cycloaaducts at higher temperature may be a consequence of barrier for s-trans to s-cis transformation of 1-azadienes.