Design and Development of Stable Nanocrystalline High-Entropy Alloy: Coupling Self-Stabilization and Solute Grain Boundary Segregation Effects

Grain growth is prevalent in nanocrystalline (NC) materials at low homologous temperatures. Solute element addition is used to offset excess energy that drives coarsening at grain boundaries (GBs), albeit mostly for simple binary alloys. This thermodynamic approach is considered complicated in multi-component alloy systems due to complex pairwise interactions among alloying elements. Guided by empirical and GB-segregation enthalpy considerations for binary-alloy systems, a novel alloy design strategy, the "pseudo-binary thermodynamic" approach, for stabilizing NC-high entropy alloys (HEAs) and other multi-component-alloy variants is proposed. Using Al25 Co25 Cr25 Fe25 as a model-HEA to validate this approach, Zr, Sc, and Hf, are identified as the preferred solutes that would segregate to HEA-GBs to stabilize it against growth. Using Zr, NC-Al25 Co25 Cr25 Fe25 HEAs with minor additions of Zr are synthesized, followed by annealing up to 1123 K. Using advanced characterization techniques- in situ X-ray diffraction (XRD), scanning/transmission electron microscopy (S/TEM), and atom probe tomography, nanograin stability due to coupling self-stabilization and solute-GB segregation effects is reported in HEAs up to substantially high temperatures. The self-stabilization effect originates from the preferential GB-segregation of constituent HEA-elements that stabilizes NC-Al25 Co25 Cr25 Fe25 up to 0.5Tm (Tm -melting temperature). Meanwhile, solute-GB segregation originates from Zr segregation to NC-Al25 Co25 Cr25 Fe25 GBs; this results in further stabilization of the phase and grain-size (≈14 nm) up to ≈0.58 and ≈0.64Tm , respectively.

Polidocanol sclerotherapy for the treatment of aneurysmal bone cyst, with or without pathological fractures: A prospective, comparative study

Introduction

Polidocanol sclerotherapy in the treatment of aneurysmal bone cysts (ABCs) with or without pathological fractures has been a topic of debate. While some studies recommend intralesional curettage as the preferred treatment, others suggest intralesional sclerosants as an effective alternative.

Material and methods

This study evaluates the use of polidocanol-based percutaneous sclerosant therapy in 28 patients with ABCs, of which 8 patients had pathological fracture. The patients received injections every four weeks based on clinical and radiological evaluation of the cyst, and the study assessed the results and complications of the treatment.

Results

In group A (without pathological fractures), 14 out of 17 (82.4 %) lesions healed without any significant residual lesion. Three out of 17 (17.6 %) patients required further surgical intervention and were treated by curettage and bone grafting, definitively. Minor local inflammatory reaction was observed in 3 patients, which resolved without intervention within 3-4 days. In group B, all the 8 patients (100 %) with pathological fracture in their lesions healed as Grade 1 healing, without any significant residual lesion. One patient developed an episode of anesthesia related complication (delayed recovery) which resolved within an hour, without any residual effect. At final follow up, no recurrence was seen in any patient.

Conclusion

The study concludes that polidocanol sclerotherapy is an effective treatment option for patients with ABCs, with or without pathological fractures, and has the potential to become the new treatment of choice for pathological fractures due to its low invasiveness, low morbidity, and affordability. However, further research is needed to confirm the efficacy of polidocanol sclerotherapy in larger patient populations and to compare its effectiveness with other treatment options.

Utility of Median-to-Ulnar Sensory Comparative Nerve Conduction Study to Increase Diagnostic Accuracy in Mild Carpal Tunnel Syndrome

Electro-physiological diagnosis of mild Carpal Tunnel Syndrome (CTS) based on traditional median motor and sensory studies are often inconclusive. Therefore, we wanted to investigate the utility of Median-to-Ulnar Sensory Conduction studies in diagnosis of mild CTS. Data from Nerve conduction study (NCS) of 82 cases with symptoms suggestive of CTS from September 2017 to October 2020 attending electrophysiology department of Mount Adora Hospital, Sylhet, Bangladesh was selected for study. About 54(66.0%) out of 82 symptomatic patients were diagnosed as CTS by the conventional method, and 28(34.0%) patients required further investigation as their test report were found to be inconclusive. combining methods showed 70(85.37%) were found to be positive and 12(14.63%) were negative in comparison study. Thus, it can be concluded that those patients found to be negative in conventional methods; comparison method is an option for diagnostic confirmation.

Warranty costs analysis under accelerated life test for power Ishita distribution with type-I censored data

Purpose

In this paper, the authors design accelerated life test and provide its application in the field of accelerated life test. The authors use maximum likelihood estimation method as a parameter estimation method.

Design/methodology/approach

In this paper we design accelerated life test and provide its application in the field of accelerated life test. The authors use maximum likelihood estimation method as a parameter estimation method.

Findings

In this study, the authors design accelerated life test under Type-I censoring when the lifetime of test items follows PID and also provides its application in the field of warranty policy. The following conclusion is made on the basis of this study. (1) An inverse relationship is shown between the shape parameter with the expected total cost and expected cycle time, while the shape parameter directly relates to the expected cost rate (see Table 5). (2) A direct relationship is shown between the scale parameter with the expected total cost and expected time cycle, while the inverse relationship is shown with the expected cost rate (see Table 5). (3) An inverse relationship is shown between the replacement age and the expected cost rate, while there are direct relationships between expected total cost and expected time cycle (see Table 5).

Originality/value

This paper is neither published or neither accepted anywhere.

Numerical simulation and optimization of CsPbI3-based perovskite solar cell to enhance the power conversion efficiency

In this study, we investigated the potential of CsPbI3 as an absorber material for use in perovskite solar cells (PSCs). To optimize the device, we used TiO2 as the electron...

Effect of Various Electron and Hole Transport Layers on the Performance of CsPbI3-Based Perovskite Solar Cells: A Numerical Investigation in DFT, SCAPS-1D, and wxAMPS Frameworks

CsPbI₃ has recently received tremendous attention as a possible absorber of perovskite solar cells (PSCs). However, CsPbI₃-based PSCs have yet to achieve the high performance of the hybrid PSCs. In this work, we performed a density functional theory (DFT) study using the Cambridge Serial Total Energy Package (CASTEP) code for the cubic CsPbI₃ absorber to compare and evaluate its structural, electronic, and optical properties. The calculated electronic band gap (E _g) using the GGA-PBE approach of CASTEP was 1.483 eV for this CsPbI₃ absorber. Moreover, the computed density of states (DOS) exhibited the dominant contribution from the Pb-5d orbital, and most charges also accumulated for the Pb atom as seen from the electronic charge density map. Fermi surface calculation showed multiband character, and optical properties were computed to investigate the optical response of CsPbI₃. Furthermore, we used IGZO, SnO₂, WS₂, CeO₂, PCBM, TiO₂, ZnO, and C₆₀ as the electron transport layers (ETLs) and Cu₂O, CuSCN, CuSbS₂, Spiro-MeOTAD, V₂O₅, CBTS, CFTS, P3HT, PEDOT:PSS, NiO, CuO, and CuI as the hole transport layers (HTLs) to identify the best HTL/CsPbI₃/ETL combinations using the SCAPS-1D solar cell simulation software. Among 96 device structures, the best-optimized device structure, ITO/TiO₂/CsPbI₃/CBTS/Au, was identified, which exhibited an efficiency of 17.9%. The effect of the absorber and ETL thickness, series resistance, shunt resistance, and operating temperature was also evaluated for the six best devices along with their corresponding generation rate, recombination rate, capacitance-voltage, current density-voltage, and quantum efficiency characteristics. The obtained results from SCAPS-1D were also compared with wxAMPS simulation results.

Managing Traumatic Brain Injury During the Coronavirus Disease 2019 Pandemic-A Case-Matched Controlled Analysis of Immediate Outcomes

OBJECTIVE

The primary objective of this study was to evaluate the outcome of patients with traumatic brain injury (TBI) during the coronavirus disease 2019 (COVID-19) pandemic and to compare their outcome with case-matched controls from the prepandemic phase.

METHODS

This is a retrospective case-control study in which all patients with TBI admitted during COVID-19 pandemic phase (Arm A) from March 24, 2020 to November 30, 2020 were matched with age and Glasgow Coma Scale score-matched controls from the patients admitted before March 2020 (Arm B).

RESULTS

The total number of patients matched in each arm was 118. The length of hospital stay (8 days vs. 5 days; P < 0.001), transit time from emergency room to operation room (150 minutes vs. 97 minutes; P = 0.271), anesthesia induction time (75 minutes vs. 45 minutes; P = 0.002), and operative duration (275 minutes vs. 180 minutes; P = 0.002) were longer in arm A. Although the incidence of fever and pneumonia was significantly higher in arm A than in arm B (50% vs. 26.3%, P < 0.001 and 27.1% vs. 1.7%, P < 0.001, respectively), outcome (Glasgow Outcome Scale-Extended) and mortality (18.6% vs. 14.4% respectively; P = 0.42) were similar in both the groups.

CONCLUSIONS

The outcome of the patients managed for TBI during the COVID-19 pandemic was similar to matched patients with TBI managed at our center before the onset of the COVID-19 pandemic. This finding suggests that the guidelines followed during the COVID-19 pandemic were effective in dealing with patients with TBI. This model can serve as a guide for any future pandemic waves for effective management of patients with TBI without compromising their outcome.

Epidemiology and impact of frailty in patients with atrial fibrillation in Europe

BACKGROUND

Frailty is a medical syndrome characterised by reduced physiological reserve and increased vulnerability to stressors. Data regarding the relationship between frailty and atrial fibrillation (AF) are still inconsistent.

OBJECTIVES

We aim to perform a comprehensive evaluation of frailty in a large European cohort of AF patients.

METHODS

A 40-item frailty index (FI) was built according to the accumulation of deficits model in the AF patients enrolled in the ESC-EHRA EORP-AF General Long-Term Registry. Association of baseline characteristics, clinical management, quality of life, healthcare resources use and risk of outcomes with frailty was examined.

RESULTS

Among 10,177 patients [mean age (standard deviation) 69.0 (11.4) years, 4,103 (40.3%) females], 6,066 (59.6%) were pre-frail and 2,172 (21.3%) were frail, whereas only 1,939 (19.1%) were considered robust. Baseline thromboembolic and bleeding risks were independently associated with increasing FI. Frail patients with AF were less likely to be treated with oral anticoagulants (OACs) (odds ratio 0.70, 95% confidence interval 0.55-0.89), especially with non-vitamin K antagonist OACs and managed with a rhythm control strategy, compared with robust patients. Increasing frailty was associated with a higher risk for all outcomes examined, with a non-linear exponential relationship. The use of OAC was associated with a lower risk of outcomes, except in patients with very/extremely high frailty.

CONCLUSIONS

In this large cohort of AF patients, there was a high burden of frailty, influencing clinical management and risk of adverse outcomes. The clinical benefit of OAC is maintained in patients with high frailty, but not in very high/extremely frail ones.

Association of Aortic Valve Sclerosis with Angiographic Severity of Coronary Artery Disease in Patients with Acute Coronary Syndrome, Aged ≤65 Years

Aortic valve sclerosis (AVS) represents a degenerative process that progresses with advancing age. The study was intended to find out the association between aortic valve sclerosis and the severity of CAD in patient's age ≤65 years with acute coronary syndrome. This cross-sectional analytical study was carried out in the department of cardiology, National Institute of Cardiovascular Diseases (NICVD), Dhaka, Bangladesh during a period of October 2017 to September 2018. A total of 140 Acute coronary syndrome (ACS) patients undergoing coronary angiogram during index hospitalization were included in the study. Study patients were divided into two groups on the basis of echocardiographic presence or absence of Aortic valve sclerosis (AVS), with 70 patients in each group. Group I was patients with aortic valve sclerosis and Group II was patients without aortic valve sclerosis. All patients underwent transthoracic echocardiography before they underwent coronary angiography on different days. Severity of CAD was determined by Gensini score and Vessel score. Association of traditional risk factors (smoking habit, hypertension, diabetes mellitus, dyslipidaemia and family history of CAD) with severity of CAD was investigated. Coronary angiography showed that AVS group had a higher positive rate of CAD (82.9% vs. 54.3%, p<0.001) and incidence rate of triple vessel CAD (40% vs. 14.3%, p<0.001) than non-AVS group. Gensini score had higher in AVS group than non AVS group (37.9±27.8 vs. 12.5±14.2; p<0.001). Multivariate analysis showed that AVS (p=0.01) and age (p=0.04) were independent predictors of the presence of significant coronary artery disease. The study concluded that echocardiographically detected AVS is an independent predictor of coronary artery disease severity. There is positive correlation between severity of AVS and severity of CAD in patient's age ≤65 years with ACS.

Adverse In-Hospital Outcome of Transradial PCI in Comparison to Transfemoral PCI in NSTEMI Patients during Index Hospitalization: A Single Center Study in Bangladesh

NSTEMI patients, in comparison to STEMI patients, are more at risk of bleeding, access site complication and MACE after PCI during index hospitalization. Because they get, multiple adjuvant anti-thrombotic agents before PCI than do the STEMI patients undergoing primary PCI. Transradial access (TRA) is proven to decrease those adverse in-hospital outcomes compared to transfemoral access (TFA) in STEMI patients. But very few studies were conducted in this regard considering NSTEMI patients. We observed prospectively the adverse in-hospital outcomes of total 180 NSTEMI patients who had undergone PCI through TRA (Group I = 80) and TFA (Group II = 100) during index hospitalization between October 2017 to September 2018 in National Institute of Cardiovascular Disease (NICVD), Dhaka, Bangladesh. Samples were selected purposively. Patients were followed up 2 hours after PCI and thereafter every day until discharge. Demographic and risk factor variables were almost same in both groups. TRA, compared with TFA, yielded less major bleeding (0% versus 3%, p=0.12) which was statistically non-significant. Minor bleeding was significantly less in Group I (2.5% versus 13.0%, p=0.04). Overall bleeding was also significantly less in Group I (2.5% and 10.0%; p=0.002). Access site complication was non-significantly less in Group I (0% versus 1%, p=0.91). TRA caused non-significant reduction in MACE (2.5% versus 5%; p=0.38) but significant reduction of total adverse in-hospital outcome (5% versus 20%, p=0.006%). In this study TRA seems to have less adverse in-hospital outcome than TFA in NSTEMI patients undergoing PCI during index hospitalization.

Short- and Long-Term Effects of Drought on Selected Causes of Mortality in Northern Bangladesh

Drought has exacerbated morbidity and mortality worldwide. Here, a time series study was conducted in northern Bangladesh to evaluate the impact of drought on selected causes of mortality during 2007-2017. Rainfall and temperature data from six meteorological stations were used to analyze drought and non-drought periods and to categorize mild, moderate, severe, and extreme drought based on the 3-month and 12-month Standardized Precipitation Index (SPI) and Standardized Precipitation Evaporation Index (SPEI). A generalized linear model with Poisson regression with log link, a negative binomial with log link, and a zero-inflated Poisson model were used to determine associations between drought severity and mortality. The SPI and SPEI produced slightly different analysis results. Compared with the SPEI, the SPI showed a stronger and more sensitive correlation with mortality. The relative risk for respiratory disease mortality was high, and Saidpur was the most vulnerable area. Health care expenditure was negatively associated with mortality. High temperatures during the drought period were associated with suicide-related mortality in Rajshahi. The impact of drought on mortality differed with small changes in climate. The findings of this study improve our understanding of the differences between the two most used drought indicators and the impact of drought on mortality.

The evaluation of rosemary (Rosmarinus officinalis) leaf extract inclusion in freezing medium on quality parameters of buffalo bull spermatozoa

BACKGROUND

The discrepancy between the endogenous antioxidants concentrations and free radicals results in oxidative stress and cellular injury.

OBJECTIVE

To appraise the usefulness of Rosemarinus officinalis (RO) aqueous extract in protecting buffalo spermatozoa during freezing / thawing process.

MATERIALS AND METHODS

Qualifying ejaculates from four well-restrained bulls were evaluated initially and then diluted in a freezing medium supplemented with RO-0.0, RO-0.5 %, RO-1.0%, RO-2.0 %, and RO-4.0 %, cooled to 4 degree C in 2 h, equilibrated for 4 h at 4 degree C, packed in straws, and cryopreserved, and thawed at 37 degree C for 30 s followed by evaluation.

RESULTS

We found that freezing medium supplemented with RO-2.0 % improves progressive motility (%) compared to the control. Similarly, a lower rate of apoptosis-like changes (%) was recorded with RO-4.0 % than the control, RO-0.5 % and RO-1.0 %. This response was accompanied by an increment in viable spermatozoa. Semen samples supplemented with RO-2.0 % and RO-4.0 % displayed higher TAC (total antioxidant capacity, uM per L) and ATP (nmol/million) content than the control. In addition, semen samples supplemented with RO-2.0 % displayed lower concentrations of ROS (reactive oxygen species, 10⁴ RLU/20 min/25 million) than the control and RO-0.05 %. Also LPO (lipid peroxidation, uM per L) with RO-2.0 % and RO-4.0 % was lower than the control.

CONCLUSION

The inclusion of rosemary aqueous extract ameliorates motility features, structural and functional parameters, viability, TAC and ATP content of bull sperm. Conversely, the inclusion of rosemary aqueous extract alleviates apoptosis-like changes, ROS and LPO in comparison to the control. Further studies are required to determine the mechanism of action of rosemary aqueous extract in ameliorating semen quality and fertility of buffalo spermatozoa. doi.org/10.54680/fr22210110712.

The Effects of Drought Severity and Its Aftereffects on Mortality in Bangladesh

Background

Drought has been a considerable problem for many years in northern Bangladesh. However, the health impacts of drought in this region are not well understood.

Methods

This study analyzed the impact of drought duration and severity on select causes of mortality in northern Bangladesh. Rainfall data from three meteorological stations (Rangpur, Dinajpur and Nilphamari) in northern Bangladesh were used to assess drought and non-drought periods, and the Standardized Precipitation Index was used to categorize mild, moderate, severe, and extreme drought. Mortality data from 2007 to 2017 for the three areas were collected from the Sample Vital Registration System, which is a survey of 1 million people. The generalized linear model with Poisson regression link was used to identify associations between mortality and the drought severity and 1-month preceding SPI.

Results

Only severe and extreme drought in the short-term drought periods affected mortality. Long-term drought was not associated with natural cause mortality in Rangpur and Nilphamari. In Dinajpur, mild and moderate drought was associated with circulatory- and respiratory-related mortality.

Conclusion

The impact of drought on mortality varied by region. This study improves our understanding of how droughts affect specific causes of mortality and will help policy makers to take appropriate measures against drought impacts on selected cause of mortality. Future research will be critical to reduce drought-related risks of health.

Limberg Flap in Pilonidal Sinus: Experience in Shaheed Suhrawardy Medical College Hospital

Pilonidal sinus disease is a common anorectal condition usually seen in young adult patients. Various methods have been described over the years and there is ongoing debate regarding the ideal method. This study was conducted to evaluate the advantages, results of rhomboid excision and Limberg flap reconstruction in the management of sacrococcygeal pilonidal sinus disease. This cross-sectional study was conducted in Surgery Unit-I of Department of Surgery, Shaheed Suhrawardy Medical College Hospital, Dhaka, Bangladesh a tertiary care centre from July 2016 to November 2017. It includes 19 patients who were treated for sacrococcygeal pilonidal sinus disease by Limberg (Rhomboid) flap. All patients that underwent the procedure had good postoperative outcome with minimal postoperative discomfort and were discharged in 3-4 days. There were 3 cases with complications. Limberg flap coverage is very effective for pilonidal disease with low complication rates, reduced hospital stay, low recurrence rates, earlier healing and shorter time off-work. This technique can be easily mastered and used as an indispensable tool for treating sacrococcygeal pilonidal sinus disease.

Factors predicting loss of cervical lordosis following cervical laminoplasty: A critical review

Background:

Laminoplasty is a method of posterior cervical decompression which indirectly decompresses the spinal column. Unfortunately, many patients undergoing laminoplasty develops postoperative loss of cervical lordosis (LCL) or kyphotic alignment of cervical spine even though they have sufficient preoperative lordosis which results in poor surgical outcome.

Objective:

We would like to highlight the relationship between various radiological parameters of cervical alignment and postoperative LCL in patients undergoing laminoplasty.

Methods:

We performed extensive literature search using PubMed, Google Scholar, and Web of Science for relevant articles that report factors affecting cervical alignment following laminoplasty.

Results:

On reviewing the literature, patients with high T1 slope have more lordotic alignment of cervical spine preoperatively. They also have more chances of LCL following laminoplasty. C2–C7 sagittal vertical axis (SVA) has no role in predicting LCL following laminoplasty though patients with low T1 slope (≤20°) and high C2–C7 SVA (>22 mm) had correction of kyphotic deformity following laminoplasty. C2–C7 lordosis, Neck Tilt, cervical range of motion, and thoracic kyphosis has no predictive value for LCL. Lower value of T1 slope (T1S-CL) and CL/T1S has more incidence of developing LCL following laminoplasty. The role of C2–C3 disc angle has not yet been evaluated in patients undergoing laminoplasty. Dynamic extension reserve determines the contraction reserve of SPMLC and lower dynamic extension reserve is associated with higher chances of LCL following laminoplasty.

Conclusions:

Cervical lordotic alignment is important in maintaining cervical sagittal balance which ultimately is responsible for global spinal sagittal balance and horizontal gaze. Among various radiological parameters, T1 Slope has been reported to be the most important factor affecting cervical alignment following laminoplasty.

The BRCA2-MEILB2-BRME1 complex governs meiotic recombination and impairs the mitotic BRCA2-RAD51 function in cancer cells

Breast cancer susceptibility gene II (BRCA2) is central in homologous recombination (HR). In meiosis, BRCA2 binds to MEILB2 to localize to DNA double-strand breaks (DSBs). Here, we identify BRCA2 and MEILB2-associating protein 1 (BRME1), which functions as a stabilizer of MEILB2 by binding to an α-helical N-terminus of MEILB2 and preventing MEILB2 self-association. BRCA2 binds to the C-terminus of MEILB2, resulting in the formation of the BRCA2-MEILB2-BRME1 ternary complex. In Brme1 knockout (Brme1-/-) mice, the BRCA2-MEILB2 complex is destabilized, leading to defects in DSB repair, homolog synapsis, and crossover formation. Persistent DSBs in Brme1-/- reactivate the somatic-like DNA-damage response, which repairs DSBs but cannot complement the crossover formation defects. Further, MEILB2-BRME1 is activated in many human cancers, and somatically expressed MEILB2-BRME1 impairs mitotic HR. Thus, the meiotic BRCA2 complex is central in meiotic HR, and its misregulation is implicated in cancer development.

The accuracy of ultrasonography for diagnosis of gallbladder polyps

INTRODUCTION

Gallbladder polyps (GBPs) are gallbladder lesions which can progress to gallbladder malignancy. The incidence has been estimated as high as 12.1% of all cholecystectomy patients. Gallbladder malignancy typically presents late, and therefore carries a poor prognosis. By identifying potential GBPs early, it would be possible to treat polyps before they undergo malignant change. The current gold standard for GBP identification is with histological examination which is performed after cholecystectomy. This study sought to assess whether radiological imaging could reliably identify GBPs and therefore guide management.

METHODS

1000 consecutive patients already undergoing cholecystectomy were sampled from two UK hospitals. Patients who underwent ultrasonography and had histological analysis of their gallbladders were selected. Overall 905 patients were included in the study.

RESULTS

There were 12 histologically confirmed GBPs in the cohort (1.33%). US correctly detected 1 GBP, with a sensitivity of 8.3% (95% CI 0.2-38.5%) and specificity of 96.0% (95% CI 94.5-97.2%). The overall accuracy was 94.8 (95% CI 93.2-96.2%).

CONCLUSION

These data show that US is an ineffective tool for GBP identification. The lack of prior operator exposure, imprecise nature of US and possible obstruction of images from underlying gallstone disease delivered a high rate of false positives.

IMPLICATIONS FOR PRACTICE

Surgical or oncological decisions regarding GBPs should not be based upon US findings alone as this would lead to unnecessary interventions. MRI should be investigated as an alternative imaging modality for GBP identification, as its differentiation of soft tissues could guide surgical management.

Corrigendum: Insight Into the Interaction Between RNA Polymerase and VPg for Murine Norovirus Replication

[This corrects the article DOI: 10.3389/fmicb.2018.01466.].

Do It Better: Cross Mattress for Chest Drain Insertion Site Security Offers Quality Outcome in Chest Trauma Patients Required Tube Thoracostomy

We examined the hypothesis that the cross mattress for chest drain insertion site security is better than that of polypropylene horizontal mattress in chest trauma patient required tube thoracostomy at the Department of Casualty Surgery, Dhaka Medical College Hospital, Dhaka, Bangladesh from January 2016 to June 2016. Accordingly we prospectively studied 50 consecutive patients who needed chest tube insertion. In 25 consecutive cases chest drain insertion site was secured with polypropylene horizontal mattress technique (Control- Group A) and another 25 consecutive patients had a cross-mattress with non-absorbable suture materials (Experimental- Group B). All chest tubes were inserted into the triangle of safety to following the BTS guideline. A baseline x-ray chest was compared with post-procedure chest x-ray. Male preponderance and young adults were comprised in both the groups; mean age in Group A and Group B was 38.7±15.5 and 37.3±14.1 respectively. Haemo-pneumothorax was the most common cause of tube thoracostomy among the trauma victims. This study shows that, polypropylene horizontal mattress results in increased chest tube site infection 52% in Control Group vs. 12% in Experimental Group (p=0.002). Although there was similar incidence of blood loss between the groups, the length of Hospital stay was significantly higher in Control Group. We conclude that cross mattress for chest drain insertion site security showed a better clinical outcome, less wound complications and less hospitalization.

Insight Into the Interaction Between RNA Polymerase and VPg for Murine Norovirus Replication

Norovirus (NoV) is a leading cause of epidemic acute non-bacterial gastroenteritis, and replicates through virion protein genome-linked (VPg)-primed or de novo RNA synthesis by RNA-dependent RNA polymerase (RdRp). VPg is a multifunctional protein that plays crucial roles in viral protein translation and genome replication. However, the interaction between the RdRp and this multifunctional VPg in NoV replication has been unknown. In this study, VPg derived from murine NoV (MNV) was found to mediate the formation of higher-order multimers or tubular fibrils of MNV RdRp, which led to significantly enhanced polymerase activity in vitro. The replication of MNV mutants containing a VPg-binding defective RdRp, based on the crystal structure of an RdRp-VPg(1-73) complex, was completely blocked in a cell culture system. Our data suggest that the interaction between RdRp and VPg plays a crucial role in the multimerization-mediated RdRp activity in vivo and consequently in MNV replication, which can provide a new target of therapeutic intervention for NoV outbreaks.

Modified blalock-taussig shunt and levosimendan for left ventricular preparation in a child with transposition of great arteries and regressed ventricle undergoing rapid 2 stage arterial switch operation

Rapid two-stage arterial switch operation (ASO) is very relevant as many patients of transposition of great arteries (TGA) present late to the hospital when primary switch either is not possible or carries a high risk of morbidity and mortality. Hence, other means apart from the traditional methods of left ventricle preparedness should be tried to help this category of patients, who are to undergo rapid two-stage ASO. We successfully used levosimendan and continuous positive airway pressure after 1^st stage operation in a patient with dTGA and regressed ventricle, which helped in left ventricular preparedness, and the child underwent rapid two-stage ASO uneventfully.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Early Outcome of Primary Repair in Colonic Injury

The management of the colon injury remains controversial in spite of a number of divergent reports during the past decade. Previously surgeons were reluctant to do primary anastomosis but now-a-days they are doing primary repair with good results. The present study is designed to see the early outcomes of primary repair in colonic injury. This prospective observational study performed at Dhaka Medical College Hospital, Dhaka, Bangladesh from January 2013 to June 2013 with allocation of 50 patients with colonic injury who underwent laparotomy with primary repair of that injury in the department of Casualty Surgery. A primary repair was performed after freshening the edges or by resection and primary anastomosis with 3.0 round-body Vicryl by single layer extra mucosal interrupted suture. Data processed using software SPSS version 16.0. For all analytical results a p value <0.05 was considered significant. In this study the commonest site of injury were transvers colon and sigmoid colon 38.0% in each. Out of 50 respondents, 5(10.0%) developed burst abdomen, 1(2.0%) developed entero-cutaneous fistula with none had paralytic ileus or septicaemia or pelvic collection. No mortality observed. This study showed that the increasing in colon injury scale (CIS) score culminate into increasing rate of postoperative complication & post operative complications were more at left colon (24%). On basis of our findings, we recommend the primary repair is a safe and effective surgical technique for addressing the large gut injury. Unnecessary proximal diversions should be avoided. According to our experience, we believe that the policy of primary repair of colon injuries can be applied more liberally in majority of patients with high success rate.

Identification of Non-nucleoside Human Ribonucleotide Reductase Modulators

Ribonucleotide reductase (RR) catalyzes the rate-limiting step of dNTP synthesis and is an established cancer target. Drugs targeting RR are mainly nucleoside in nature. In this study, we sought to identify non-nucleoside small-molecule inhibitors of RR. Using virtual screening, binding affinity, inhibition, and cell toxicity, we have discovered a class of small molecules that alter the equilibrium of inactive hexamers of RR, leading to its inhibition. Several unique chemical categories, including a phthalimide derivative, show micromolar IC50s and KDs while demonstrating cytotoxicity. A crystal structure of an active phthalimide binding at the targeted interface supports the noncompetitive mode of inhibition determined by kinetic studies. Furthermore, the phthalimide shifts the equilibrium from dimer to hexamer. Together, these data identify several novel non-nucleoside inhibitors of human RR which act by stabilizing the inactive form of the enzyme.

RISUG: an intravasal injectable male contraceptive

Over the last two decades RISUG has been drawing attention in the field of male contraception. It promises to sterile men for a period of up to 10-15 years. According to recent studies in animal models, it proves to be completely reversible. Practically, there are no better options available that can assure complete sterility and precise reversibility. Regardless of so much of information available, RISUG is still holding up for many reasons, firstly, the available information engender bewilderment such as what is this copolymer, how does it work and is reversal really possible? Secondly, advancement of this outstanding invention is drastically slow and thirdly, effects of long-term contraception with RISUG and reports on evaluation of anomalies (if any) in F 1 , F 2 progenies, are lacking. In this review the lacunae as well as advances in the development of RISUG in the light of published work and available resources are pointed out. Formulation of the RISUG, its mode of action and clinical trials have been addressed with particular emphasis.

Profile of atherosclerotic risk factors and management in patients of peripheral arterial disease at a tertiary care teaching hospital of north India

Peripheral arterial disease, being a manifestation of systemic atherosclerosis, carries a high risk of adverse cardiovascular events. Secondary medical prevention therapies of same magnitude as that for coronary artery disease are recommended for peripheral arterial disease patients also. Available evidence indicates that this condition commonly remains underdiagnosed and undertreated. There is lack of any report about management of these patients in India. The objectives of the present study were to characterize the atherosclerotic risk factor profile and pattern of drug prescription for patients of peripheral arterial disease at a tertiary care teaching hospital and to compare this management with standard guidelines. Data were collected from prescriptions of patients attending cardiothoracic and vascular surgery outpatient department with diagnosis of atherosclerotic peripheral arterial disease from July 2012 to Jun 2013. One hundred twenty prescriptions were analysed. The mean age (±SD) of patients was 53±7.18 years and 23.3% were females. History of smoking, either past or present, was present in 91.6% patients. History of ischemic heart disease was present in 25%, while 26.7% patients were diabetic. Mean number of cardiovascular risk factors was 2.6. The percentage of eligible patients who were receiving a particular drug was 100% for aspirin and statins, 48.3% for angiotensin converting enzyme inhibitors, 46.7% for beta blockers and 66.7% for cilostazol. The vascular surgeons of this centre are using antiplatelet agents and statins adequately for peripheral arterial disease. The prescription of angiotensin converting enzyme inhibitors, beta blockers and cilostazol is low. Exercise therapy and smoking cessation need more attention.

Crystal structures of murine norovirus-1 RNA-dependent RNA polymerase in complex with 2-thiouridine or ribavirin

Murine norovirus-1 (MNV-1) shares many features with human norovirus (HuNoV) and both are classified within the norovirus genus of Caliciviridae family. MNV-1 is used as the surrogate for HuNoV research since it is the only form that can be grown in cell culture. HuNoV and MNV-1 RNA dependent RNA polymerase (RdRp) proteins with the sequence identity of 59% show essentially identical conformations. Here we report the first structural evidence of 2-thiouridine (2TU) or ribavirin binding to MNV-1 RdRp, based on the crystal structures determined at 2.2Å and 2.5Å resolutions, respectively. Cellular and biochemical studies revealed stronger inhibitory effect of 2TU on the replication of MNV-1 in RAW 264.7 cells, compared to that of ribavirin. Our complex structures highlight the key interactions involved in recognition of the nucleoside analogs which block the active site of the viral RNA polymerase.

Temporal changes in glucose and insulin homeostasis after biliopancreatic diversion and laparoscopic adjustable gastric banding

BACKGROUND

Obesity surgery is associated with improvement in type 2 diabetes mellitus. Our aim was to examine the effects of biliopancreatic diversion (BPD) and laparoscopic adjustable gastric banding (LAGB) on the body mass index, fasting insulin level, glucose level, and insulin resistance in morbidly obese subjects with type 2 diabetes mellitus. The setting was the Department of Surgery, Morriston Hospital (Swansea, Wales, United Kingdom).

METHODS

A total of 13 morbidly obese patients (7 BPD, 6 LAGB) underwent serial measurements of fasting glucose and insulin at baseline, immediately after surgery (days 1-7), and 1, 6, and 12 months postoperatively. The homeostasis model of assessment-insulin resistance was calculated.

RESULTS

In the BPD group, the glucose levels had normalized by day 3 (5.6 ± 1 mmol/L) and the difference was statistically significant at 6 and 12 months postoperatively (5 ± .7 and 4.4 ± .5 mmol/L, respectively). The insulin levels had improved from day 1, and the difference was statistically significant at days 2, 5, 6, and 7 (19 ± 9, 14.2 ± 7, 15.2 ± 8, and 17.4 ± 8 mU/L, respectively). All diabetes medications were stopped on the fourth postoperative day. In the LAGB group, no statistically significant changes were seen in the glucose levels. Statistically significant changes in insulin were seen on days 1 and 2 (19 ± 13 and 13 ± 6.5 mU/L, respectively). The homeostatic model of assessment-insulin resistance had improved in both groups (BPD, 1.6 ± 1.2, P < .01; and LAGB, 4.3 ± 1.4, P < .05).

CONCLUSION

BPD causes immediate remission of type 2 diabetes mellitus. Leptin might play an important role in the early improvement of insulin resistance in fasting states after BPD. In the LAGB group, glucose homeostasis improved, but the patients still required diabetes medications, although the dosages were reduced.

Crystal structures of murine norovirus-1 RNA-dependent RNA polymerase

Norovirus is one of the leading agents of gastroenteritis and is a major public health concern. In this study, the crystal structures of recombinant RNA-dependent RNA polymerase (RdRp) from murine norovirus-1 (MNV-1) and its complex with 5-fluorouracil (5FU) were determined at 2.5 Å resolution. Crystals with C2 symmetry revealed a dimer with half a dimer in the asymmetrical unit, and the protein exists predominantly as a monomer in solution, in equilibrium with a smaller population of dimers, trimers and hexamers. MNV-1 RdRp exhibited polymerization activity with a right-hand fold typical of polynucleotide polymerases. The metal ion modelled in close proximity to the active site was found to be coordinated tetrahedrally to the carboxyl groups of aspartate clusters. The orientation of 5FU observed in three molecules in the asymmetrical unit was found to be slightly different, but it was stabilized by a network of favourable interactions with the conserved active-site residues Arg185, Asp245, Asp346, Asp347 and Arg395. The information gained on the structural and functional features of MNV-1 RdRp will be helpful in understanding replication of norovirus and in designing novel therapeutic agents against this important pathogen.

Enhanced adherence to HCV therapy with higher dose ribavirin formulation: final analyses from the ADHERE registry

BACKGROUND

Poor adherence to Hepatitis C virus (HCV) treatment is an important cause of treatment failure. Traditional ribavirin 200 mg (RBV) treatment is associated with a significant daily pill burden. RibaPak (RBP), available as 400 mg and 600 mg ribavirin tablets, offers simplified dosing at two pills daily.

AIM

To examine whether improved adherence was associated with RBP vs. RBV.

METHODS

Accurate Dosing in Hepatitis C: Examining the RibaPak Experience (ADHERE) was a U.S., multi-centre, prospective registry capturing data on adherence with RBP vs. RBV in adults with HCV. Adherence was measured by the proportion of subjects remaining on treatment at weeks 4, 12 and 24; by pill counts; and by the proportion of subjects who took > or = 80% of their prescribed dose.

RESULTS

A total of 503 patients (RBP = 346, RBV = 157) from 33 sites were included. A greater proportion of RBV vs. RBP subjects prematurely discontinued treatment. At 12 and 24 weeks, a greater proportion of RBP vs. RBV subjects took > or = 80% of their prescribed doses (P < 0.05). For patients who remained on treatment, the mean milligrams missed per day was significantly greater for RBV vs. RBP at 24 weeks.

CONCLUSIONS

First line treatment with RBP may offer the best prospect for less discontinuation and improved treatment adherence.

Influence of bariatric surgery on indices of cardiac autonomic control

BACKGROUND

Obesity is associated with reduced heart rate variability (HRV), reflecting detrimental changes in cardiac regulation by the autonomic nervous system (ANS). Weight loss reverses this change and ANS dysfunction is thought to have a role in obesity-related cardiac pathology. Few studies have examined the influence of weight-reduction (bariatric) surgery on cardiac autonomic control. This study therefore sought to assess longitudinal changes in indices of cardiac autonomic control following two types of bariatric procedure, laparascopic gastric banding (LGB) and biliopancreatic diversion (BPD).

METHODS

Eleven morbidly obese subjects aged 47.8 +/- 7.9 years (mean+/-SD) with BMI 48.2 +/- 6.9 kg x m(-2) underwent weight-reduction surgery: five received BPD and six received LGB. Holter ECG was recorded and HRV was quantified together with a QT variability index (QTVI), a complexity index (SampEn), and a fractal (scaling) index (DFAalpha). Repeated measures ANOVA compared the indices for the two groups as a function of time (1, 6 and 12 months follow-up).

RESULTS

BMI was reduced by up to 24% (p=0.008) post-surgery despite patients remaining obese at one-year follow-up. Several indices showed prompt and persistent improvement with progressive weight loss, QTVI being the most sensitive discriminator of recovery time (F(3,216)=16.86; p<0.0005; eta(2)=0.190). Autonomic responsiveness was functionally normal throughout. The bariatric procedures induced similar changes in cardiac autonomic control, despite their differing mechanisms of action.

CONCLUSIONS

This pilot study suggests that the mechanism responsible for improving cardiac regulation following bariatric surgery might be the weight loss itself. Furthermore, post-surgery improvement in QTVI implies that weight loss reduces the risk of ventricular arrhythmic events.

Linear and nonlinear characteristics of heart rate time series in obesity and during weight-reduction surgery

Obesity is associated with abnormal cardiac regulation by the autonomic nervous system (ANS), this being reversed by weight loss. Bariatric (weight-reduction) surgery can induce substantial long-term weight reductions. This study compares the acute influence on ANS control of two different types of bariatric surgery involving laparascopic and open procedures. To distinguish between the cardiac influences of surgery and obesity, we perform the same analysis for laparascopic surgery in non-obese patients. Eight morbidly obese and five non-obese patients underwent surgery. Obese patients received either laparoscopic procedures (group A: n = 5, BMI = 44.3 +/- 2.7 kg m(2)) or open procedures (group B: n = 3, BMI = 55.2 +/- 4.5 kg m(2)) and non-obese patients received a laparoscopic procedure (group C: n = 5, BMI = 30.8 +/- 5.8 kg m(-2)). Holter ECG was recorded and heart rate variability (HRV) was quantified together with measures of complexity (sample entropy) and structure (Hurst coefficient, scaling coefficient) of the heart rate data. Multifractal characteristics of heart rate data, not previously reported for obese patients, are also quantified and interpreted. Mixed model ANOVA was used to assess the magnitudes of each quantified variable, with surgical group and perioperative time as main factors. HRV measures were influenced only during anaesthesia (LFn increase: p = 0.009; HFn decrease: p = 0.033) and did not discriminate between patient groups. Multifractality was the only characteristic of heart rate data that discriminated between patient groups, being significantly (p < 0.001) greater in non-obese (group C) compared with obese patients (groups A and B, who had similar multifractal properties). Multifractality was also enhanced during anaesthesia (p = 0.028) but did not differ for other stages. We conclude that obesity per se rather than response to surgery is the cause of reduced multifractality. Reduced multifractality in obesity might reflect a diminished 'scaling' or 'collective response' across the multiple autonomic modulators of heart rate. The multifractal method appears to be a more sensitive measure of integrated cardiac autonomic function than linear methods for these patients.

2-Thiazolylimino/heteroarylimino-5-arylidene-4-thiazolidinones as new agents with SHP-2 inhibitory action

SHP-2, a nonreceptor protein tyrosine phosphatase encoded by the PTPN11 gene, mediates cell signaling by growth factors and cytokines via the RAS/MAP kinase pathway. Somatic mutations in PTPN11 gene account for approximately 18% of juvenile myelomonocytic leukemia (JMML) patients. Moreover, SHP-2 mutations leading to continuously active enzyme were found in more than 50% of Noonan syndrome patients and are considered to be responsible for the high tendency of these patients to juvenile leukemias and other cancer types. Recently SHP-2 became a new drug target, but till now little has been done in this field. In the present study, 17 2-thiazolylimino/heteroarylimino-5-arylidene-4-thiazolidinones divided into three series of derivatives bearing thiazole-, benzo[d]thiazole-, and benzo[d]isothizole rings were tested for SHP-2 inhibitory activity. Most of the compounds were good SHP-2 inhibitors. Benzo[d]thiazole derivatives exhibited the best inhibitory action. Docking studies revealed that hydrophobic interactions and hydrogen bond formation stabilize enzyme-inhibitor complex.

Internet resources in GPCR modelling

G-Protein coupled receptors (GPCRs), one of the most important families of drug targets, belong to the super family of integral membrane proteins characterized by seven transmembrane helices. Because they are difficult to crystallize, the three dimensional structure of these receptors have not yet been determined by X-ray crystallography, except one. In the absence of a 3-D structure, in-silico approaches for solving the structure of this class of proteins are widely used and provide valuable information for structure based drug design. There are several web servers and computer programs available that automate the modelling process of GPCRs. Some of these include Modeller, Swiss-Model server, Homer, etc. Using these tools reliable homology models of human histamine H1 receptor (HRH1) and thrombin receptor (PAR-1) have been generated which explain the binding mode of the standard antagonists of these receptors and may be useful in designing their novel antagonists.

Obesity, metabolic syndrome and sleep apnoea: all pro-inflammatory states

Obesity is associated with significant morbidity and mortality and is increasing in prevalence worldwide. Associated conditions include insulin resistance (IR), diabetes, hypertension and dyslipidaemia; a clustering of these has recently been termed as metabolic syndrome. Weight gain is a major predictor of the metabolic syndrome with waist circumference being a more sensitive indicator than body mass index as it reflects both abdominal subcutaneous adipose tissue and visceral adipose tissue (VAT). VAT has more metabolic activity and secretes a number of hormones and pro-inflammatory cytokines which are linked with the metabolic abnormalities listed above. Central obesity also increases the risk of obstructive sleep apnoea syndrome (OSAS), where the sleep disordered breathing may also independently lead to/or exacerbate IR, diabetes and cardiovascular risk. The contribution of OSAS to the metabolic syndrome has been under-recognized. The putative mechanisms by which OSAS causes or exacerbates these other abnormalities are discussed. We propose that activation of nuclear factor kappa B by stress hypoxia and/or by increased adipokines and free fatty acids released by excess adipose tissue is the final common inflammatory pathway linking obesity, OSAS and the metabolic syndrome both individually and, in many cases, synergistically.

Gastro-ileal stenosis and gastroparesis after a biliopancreatic diversion

Biliopancreatic diversion (BPD) is a very effective bariatric operation particularly for super-obese patients (BMI > or = 50 kg/m(2)). We present the development of a stricture at the gastro-ileal anastomotic site, with subsequent dilatation and aperistalsis of the stomach in a female patient who had undergone a standard open Scopinaro BPD. The patient remained symptomatic and persisted in losing weight, despite endoscopic balloon dilatations of the stricture and surgical revision of the anastomosis. She finally underwent conversion to a standard Roux-en-Y proximal gastric bypass. We describe the development of the stricture after the use of the stapling gun, subsequent gastric dilatation and dysmotility.

Identification of a quantitative trait locus on rat chromosome 4 that is strongly linked to femoral neck structure and strength

Risk factors for osteoporotic hip fracture include reduced bone mineral density and poor structure of the femoral neck, both of which are heritable traits. Previously, we showed that despite similar body size, Fischer 344 (F344) rats have significantly different skeletal traits compared with Lewis (LEW) rats. To identify a gene or genes regulating fracture risk at the femoral neck, we mapped quantitative trait loci (QTL) for femoral neck density and structure phenotypes using a 595 F2 progeny derived from the inbred F344 and LEW strains of rats. Femoral neck phenotypes included volumetric bone mineral density (vBMD), neck width, femoral neck cross-sectional area and polar moment of inertia (Ip). A 20-cM genome-wide scan was performed using 118 microsatellite markers and linkage analysis was conducted to identify chromosomal regions harbor QTL for femoral neck phenotypes. Strong evidence of linkage (P<0.01) to femoral neck vBMD was observed on chromosomes (Chrs) 1, 2, 4, 5, 7, 10 and 15. QTL affecting femoral neck structure and biomechanical properties were detected only on Chr 4 where the F344 alleles were shown to improve femoral neck structure, whereas these alleles had no effect on bone measurements at the lumbar spine and only modest effects at the femoral midshaft. In contrast, QTL on Chrs 1, 2 and 10 affected multiple skeletal sites. Several QTL regions in this study are homologous to human chromosomal regions, where linkage to femoral neck and related phenotypes has been reported previously. These findings represent an important first step in localizing and identifying genes that influence hip fragility.