Formation of partially embedded Au nanostructures: Ion beam irradiation on thin film.

The Au partially embedded nanostructure (PEN) is synthesized by ion irradiation on an Au thin film deposited on a glass substrate using a 50 keV Ar ion. Scanning electron microscopy results show ion beam-induced restructuring from irregularly shaped nanostructures (NSs) to spherical Au NSs, and further ion irradiation leads to the formation of well-separated spherical nanoparticles. Higuchi's algorithm of surface analysis is utilized to find the evolution of surface morphology with ion irradiation in terms of the Hurst exponent and fractal dimension. The Au PEN is evidenced by Rutherford backscattering spectrometry and optical studies. Also, the depth of the mechanism behind synthesized PEN is explained on the basis of theoretical simulations, namely, a unified thermal spike and a Monte Carlo simulation consisting of dynamic compositional changes (TRIDYN). Another set of plasmonic NSs was formed on the surface by thermal annealing of the Au film on the substrate. Glucose sensing has been studied on the two types of plasmonic layers: nanoparticles on the surface and PEN. The results reveal the sensing responses of both types of plasmonic layers. However, PEN retains its plasmonic behavior as the NSs are still present after washing with water, which demonstrates the potential for reusability. RESEARCH HIGHLIGHTS: Synthesis of PENs by ion irradiation Utilization of Higuchi's algorithm to explore the surface morphology. Unified thermal spike and TRIDYN simulations being used to explain the results. Glucose is only used as a test case for reusability of substrate.

Scoring tools to identify TB patients facing catastrophic costs in the Philippines.

BACKGROUND: This study was to meet a practical need to design a simple tool to identify TB patients who may potentially be facing catastrophic costs while seeking TB care in the public sector. Such a tool may help prevent and address catastrophic costs among individual patients. METHODS: We used data from the national TB patient cost survey in the Philippines. We randomly allocated TB patients to either the derivation or validation sample. Using adjusted odds ratios (ORs) and ß coefficients of logistic regression, we developed four scoring systems to identify TB patients who may be facing catastrophic costs from the derivation sample. We validated each scoring system in the validation sample. RESULTS: We identified a total of 12 factors as predictive indicators associated with catastrophic costs. Using all 12 factors, the ß coefficients-based scoring system (area under the curve [AUC] 0.783, 95% CI 0.754-0.812) had a high validity. Even with seven selected factors with OR > 2.0, the validity remained in the acceptable range (ß coefficients-based: AUC 0.767, 95% CI 0.737-0.798). CONCLUSION: The ß coefficients-based scoring systems in this analysis can be used to identify those at high risk of facing catastrophic costs due to TB in the Philippines. Operational feasibility needs to be investigated further to implement this in routine TB surveillance.

CONTEXTE: Cette étude visait à répondre à un besoin pratique de concevoir un outil simple pour identifier les patients atteints de TB qui pourraient potentiellement être confrontés à des coûts catastrophiques lorsqu'ils recherchent des soins de TB dans le secteur public. Un tel outil pourrait aider à prévenir et à traiter les coûts catastrophiques chez les patients individuels. MÉTHODES: Nous avons utilisé des données de l'enquête nationale sur les coûts des patients atteints de TB aux Philippines. Nous avons réparti aléatoirement les patients atteints de TB dans l'échantillon de dérivation ou de validation. À l'aide des odds ratio (OR) ajustés et des coefficients ß de la régression logistique, nous avons développé quatre systèmes de notation pour identifier les patients atteints de TB qui pourraient être confrontés à des coûts catastrophiques à partir de l'échantillon de dérivation. Nous avons validé chaque système de notation dans l'échantillon de validation. RÉSULTATS: Nous avons identifié un total de 12 facteurs en tant qu'indicateurs prédictifs associés à des coûts catastrophiques. En utilisant les 12 facteurs, le système de notation basé sur les coefficients ß (aire sous la courbe [AUC] 0,783 ; IC 95% 0,754­0,812) avait une validité élevée. Même avec sept facteurs sélectionnés avec OR > 2,0, la validité est restée dans la plage acceptable (basée sur les coefficients ß : AUC 0,767 ; IC 95% 0,737­0,798). CONCLUSION: Les systèmes de notation basés sur les coefficients ß dans cette analyse peuvent être utilisés pour identifier les personnes à haut risque de faire face à des coûts catastrophiques liés à la TB aux Philippines. La faisabilité opérationnelle doit être étudiée plus avant pour mettre en œuvre cela dans la surveillance de routine de la TB.

Comparison of Two Entry Methods for Laparoscopic Port Entry.

Background The first step in laparoscopic surgery is to establish the pneumoperitoneum for which many approaches have been introduced to minimize the complications. Although controversies exist regarding the most efficient technique, till now the best entry technique is still unsettled. Objective To compare the safety, operating time and outcome of Direct Trocar Insertion with a well-established and widely practised Open Access Technique. Method This is a prospective study at Nobel Medical College Teaching Hospital from November 2019 to February 2021. Patients were grouped into either of the two groups, Group 1 for Direct Trocar Insertion and Group 2 for Open Access Technique. They were later analysed for major and minor complications of the technique and a comparison of either method was done at the end of the study period. Result A total of 823 patients were enrolled in the study. Among the study population, 411 patients had Direct Trocar Insertion while 412 patients had Open Access Technique. The majority of the operation that was done during the study period was laparoscopic cholecystectomy. Patients in the Open Access Technique group experienced more complications compared to Direct Trocar Insertion group. Conclusion Despite the fear of adopting the Direct Trocar Insertion, this is a safe, better and quick technique for laparoscopic port entry. However, any surgeon practising laparoscopic surgery should be competent to adopt either technique to overcome failure in either process during port entry.

Influence of Temperature on Graphene/ZnO Heterojunction Schottky Diode Characteristics.

The paper reports development of graphene/ZnO heterojunction Schottky diode structure and its structural and electrical characterization. Graphene is grown on copper substrate using chemical vapor deposition (CVD) and transferred on flexible substrate (indium Tin Oxide coated PET). The grown thin layer is characterized using scanning electron microscopy and Raman spectroscopy which confirm uniformity and high-quality graphene layer. The sputtered ZnO is deposited and characterized which confirms c-axis (002) orientation and uniform growth of ZnO film. Silver (Ag) as a top electrode has been deposited and I-V measurement has been done. The effect of operating temperature (300 K to 425 K) on I-V characteristics of the fabricated structure has been measured experimentally. The other diode parameters such as ideality factor and effective barrier height have been derived. The reliability of the heterojunction synthesized is proved by the diode ideality factor of 1.03 attained at 425 K. The excellent C-V characteristics (capacitance of 48pF) of the device prove that the device is an excellent candidate for application as supercapacitors. The fabricated structure can be utilized as an ultraviolet photodetector, solar cell, energy storage devices, etc.

Fractal and multifractal characteristics of swift heavy ion induced self-affine nanostructured BaF2 thin film surfaces.

Fractal and multifractal characteristics of self-affine surfaces of BaF2 thin films, deposited on crystalline Si ⟨1 1 1⟩ substrate at room temperature, were studied. Self-affine surfaces were prepared by irradiation of 120 MeV Ag(9+) ions which modified the surface morphology at nanometer scale. The surface morphology of virgin thin film and those irradiated with different ion fluences are characterized by atomic force microscopy technique. The surface roughness (interface width) shows monotonic decrease with ion fluences, while the other parameters, such as lateral correlation length, roughness exponent, and fractal dimension, did not show either monotonic decrease or increase in nature. The self-affine nature of the films is further confirmed by autocorrelation function. The power spectral density of thin films surfaces exhibits inverse power law variation with spatial frequency, suggesting the existence of fractal component in surface morphology. The multifractal detrended fluctuation analysis based on the partition function approach is also performed on virgin and irradiated thin films. It is found that the partition function exhibits the power law behavior with the segment size. Moreover, it is also seen that the scaling exponents vary nonlinearly with the moment, thereby exhibiting the multifractal nature.

Identifying multidrug resistance in previously treated tuberculosis patients: a mixed-methods study in Cambodia.

SETTING: Previously treated tuberculosis (TB) patients are a priority for drug susceptibility testing (DST) to identify cases with multidrug-resistant TB (MDR-TB). A Cambodia study found that one third of smear-positive previously treated patients had DST results. OBJECTIVE: To quantify the gaps in the detection of MDR-TB in previously treated TB patients in Cambodia, and describe health workers' perspectives on barriers, facilitators and potential interventions. DESIGN: Analysis of Cambodia's 2004-2012 case notifications and semi-structured interviews with stakeholders. RESULTS: The proportion of previously treated notifications varied significantly across provinces in 2010-2012. If there had been no attrition along the path to detecting MDR-TB among smear-positive notified cases in 2012, an estimated 75 additional MDR-TB cases could have been identified, which would double the number actually detected. Most were lost due to misclassification of previously treated patients as 'new'. Barriers include patients' reluctance to disclose and staff difficulty in eliciting treatment history, partly attributed to the availability of streptomycin (SM) only in hospitals. Facilitators include collection of sputum for DST even if previously treated patients are not receiving SM, streamlining sputum transportation and prompt reporting of results. CONCLUSION: Improved monitoring, supportive staff supervision and training, patient education, and correct classification of previously treated cases are essential for improving the detection of MDR-TB.

Culture, characterization and differentiation of cells from buffalo (Bubalus bubalis) amnion.

Stem cells present an important tool in livestock assisted reproduction and veterinary therapeutic field such as tissue engineering. We report for the first time isolation of pluripotent stem cell-like cells expressing pluripotency markers (alkaline phospahatase, OCT-4, NANOG and SOX-2) from the amnion of water buffalo (Bubalus bubalis). The cells showed no apparent abnormalities in their chromosomal profiles before and after cryopreservation. The cytochemical staining revealed that pluripotent cells were capable of undergoing directed differentiation in vitro into osteocytes. It could be inferred that amnion-derived pluripotent stem cell-like cells can be isolated, cultured for many passages and differentiated into mesoderm lineage, and may be an alternative source to mesenchymal stem cells. These cells can have applications in assisted reproduction, developmental biological and regenerative medicine.

Rectosigmoid endometriosis causing an acute large bowel obstruction: a report of a case and a review of the literature.

Endometriosis is often seen in gynecology practice and is treated medically. However, intestinal involvement of endometriosis causing acute large bowel obstruction is uncommon and is difficult to differentiate from malignancy before surgery, owing to its similar colonoscopic and radiologic findings. We report a successfully-treated case of a 30-year-old woman in which endometrial infiltration of the large bowel caused acute obstruction, requiring emergency surgery to relieve the symptom and confirm the diagnosis. We present this unusual disease in general surgical practice and also review the literature.

Piscicidal activity of leaf and bark extract of Thevetia peruviana plant and their biochemical stress response on fish metabolism.

OBJECTIVES: The leaf and bark of Thevetia peruviana (Family: Apocynaceae) plant was administered for 24 h to the freshwater fish Catla catla (Hamilton) to evaluate their piscicidal activity in laboratory and cemented pond condition. MATERIALS AND METHODS AND RESULTS: The LC0 values of lef and bark extracts of different solvents (i.e., acetone, diethyl ether, ethyl alcohol, chloroform and carbon tetrachloride) of this plant to fish Catla catla were determined. The LC50 values of acetone leaf extract of Thevetia peruviana plant is 88.80 mg/L (24h) in laboratory condition and 529.38 mg/L (24h) in cemented pond condition; acetone bark extract of this plant is 99.43 mg/L (24h) in laboratory condition and 591.78 mg/L (24h) in cemented pond condition against freshwater fish Catla catla. Similar trend was also observed in case of other solvent (i.e., diethyl ether, ethyl alcohol, chloroform and carbon tetrachloride) of leaf and bark extracts of Thevetia peruviana plant against freshwater fish Catla catla in laboratory and cemented pond conditions. The acetone leaf and bark extract of this plant was very effective in comparison to other solvent extract in both the conditions. So, the biochemical analysis is taken only acetone leaf and bark extract of Thevetia peruviana plant in laboratory condition. CONCLUSIONS: Exposure of sub-lethal doses (40% and 80% of LC,) of acetone leaf and bark extract of this plant over 24 h caused significant (P < 0.05) alterations in total protein, free amino acids, DNA & RNA, protease and acid and alkaline phosphatase activity in muscle, liver and gonadal tissues of fish Catla catla in laboratory condition.

A comparative study of early vs. delayed laparoscopic cholecystectomy in acute cholecystitis.

AIMS AND OBJECTIVES: To compare the outcome in early vs delayed laparoscopic cholecystectomy in terms of frequency of intra operative and postoperative complications and to determine the rate and reasons for conversion. MATERIALS AND METHODS: A prospective randomized clinical trial was performed in the Department of Surgery at BP Koirala Institute of Health Sciences from February 2003 to June 2004 in all patients with the diagnosis of acute calculus cholecystitis. RESULTS: Out of 145 cases, 50 cases were included in our study where 12 (24%) patients were males and 38 (76%) were females (M:F=1:3.16). The mean (SD) age of patients in early and delayed groups were 42.68 yrs (14.18) and 40.26 yrs (11.62) respectively. The mean (SD) duration of symptoms in early successful and converted groups were 109.24 hrs (43.66) and 132 hrs (49.96) respectively and the mean (SD) duration of symptoms in delayed successful and converted groups were 15.36 months (13.88) and 41 months (40.73) respectively. In early group, 17 (68%) patients had total leukocyte count more than 10,000/cmm and they had ultrasound findings suggestive of acute cholecystitis. Out of 25 patients in early group, seven had jaundice and ten had deranged liver function in the preoperative period. In early group 4 (16%) patients; and in delayed group 3 (12%) had to be converted to open cholecystectomy (P=1.00). In early group 10 (40%) and in delayed 5 (20 %) cases had intraoperative complications (P=0.122). The total hospital stay was longer in the delayed group. The postoperative hospital stay in early and delayed converted groups were higher than early and delayed successful group (P=0.081, P=0.082). CONCLUSION: Both early and delayed laparoscopic cholecystectomy is possible and safe in the treatment of acute cholecystitis.

Perforated duodenal ulcer in a young child: an uncommon condition.

Duodenal ulcer is an uncommonly diagnosed entity in children. H. pylori infection, blood group 'O' or secondary to medications like non steroidal anti-inflammatory drugs (NSAID) and corticosteroids or physiological stress in burns, head injury and mucosal ischemia are implicated as risk factors for their causation. The diagnosis is usually overlooked because of vague and variable symptoms and remote index of suspicion accounted for their low incidence in children. Undiagnosed or mistreated perforations may carry high morbidity and mortality. We report a successfully treated 41/2 year old male child who presented with features of perforation peritonitis and was incidentally found to have a perforated duodenal ulcer.

Pediatric femoral hernia.

Pediatric femoral hernias account for less than 1% of all groin hernias. Pediatric femoral hernias are rather uncommon more so in males, often overlooked, misdiagnosed and treated as inguinal hernia. Femoral hernia masquerading as inguinal hernia in a seven year old male is reported along with review of relevant literature.

Iliopsoas abscess: analysis and perspectives from an endemic region of Eastern Nepal.

OBJECTIVE: To evaluate the clinical profile and outcome in patients with iliopsoas abscess. METHODS: A descriptive study was carried out in B.P. Koirala Institute of Health Science, Dharan, Nepal from February 2005 to March 2006. The medical records of all thirty six patients admitted in surgery ward with diagnosis of iliopsoas abscess during the study period were analyzed. RESULTS: Thirty six patients were included the study. There were 22 (61.1%) males and 14 (38.9%) females with a mean age of 24.33 +/-19.19 years. Demographic distribution of the patients revealed the highest number 13 (36.1%) from Sunsari district, eastern part of the country. Right sided unilateral involvement was the most common presentation and only 2 cases had bilateral involvement. In none of our patients the dorsolumbar spine radiograph revealed any involvement of the bone. The most common complaints were pain in lower abdomen and lump in iliac fossa with flexion deformity at hip joint. All the patients underwent open surgical drainage and their outcomes were analyzed in term of cure, morbidity and mortality. Staphylococcus aureus was the most common organism 24 (61.5%) isolated. Twenty two (91.66%) of Staphylococcus aureus samples were sensitive to ciprofloxacin. There was one mortality in the group who died of septicaemia secondary to necrotizing fascitis. Six patients had wound infection, which were cured by regular dressing. CONCLUSION: On the basis of our experience and review of available relevant literature, we can conclude that a high index of suspicion and awareness of the varying clinical picture are required to diagnose this condition properly. Ultrasonography should still be the preferred imaging modality as it is cheap, safe, cost effective and readily available. Ciprofloxacin should be used as a first line drug. Image guided aspiration may be practical in selected cases having little pus and traditional open drainage should be considered without hesitation.

Toxic effect of two common Euphorbiales latices on the freshwater snail Lymnaea acuminata.

The aqueous and serially purified latex extracts of plants Euphorbia pulcherima and Euphorbia hirta (family Euphorbiaceae) have potent molluscicidal activity. Sub-lethal doses (40 and 80% of LC(50)) of aqueous and partially purified latex extracts of both the plants also significantly alter the levels of total protein, total free amino acid, nucleic acid (DNA and RNA) and the activity of enzyme protease and acid and alkaline phosphatase in nervous tissue of the snail Lymnaea acuminata in time and dose dependent manner. E. pulcherima and E. hirta are common medicinal plants of family Euphorbiaceae. E. pulcherima is useful for a variety of conditions, such as rheumatism, snakebite, asthma, obstipation, and skin-diseases. While, E. hirta is also used in cough, asthma, colic, dysentery, and genito urinary diseases.

Purification and characterization of a regiospecific lipase from Aspergillus terreus.

Aspergillus terreus lipase was purified to homogeneity with 18.0% yield. The specific activity of the enzyme increased from 20.80 to 250 U/mg of protein. Ion exchange on Q-Sepharose was highly effective in the purification process. The molecular mass of the purified enzyme was 41+/-1 kDa as determined by SDS/PAGE. The purified lipase showed excellent temperature tolerance (15-90 degreesC) and was highly thermostable, retaining 100% activity at 60 degreesC for 24 h. It showed good pH tolerance (3.0-12.0) and was stable over a pH range of 4.0-10.0 for 24 h. The activity of the enzyme was inhibited by ionic detergents, whereas non-ionic detergents stimulated enzyme activity. Mg2+ and Ca2+ ions stimulated lipase activity, whereas Co2+, Cu2+, Ni2+ and Fe3+ ions caused inhibition. The enzyme was unaffected by the metal chelator EDTA or by 2-mercaptoethanol and potassium ferrocyanide. At a concentration of 100 microM, 3,4-dichloroisocoumarin caused weak inhibition with 40% loss of activity, but diethyl p-nitrophenyl phosphate at the same concentration strongly inhibited enzyme activity (98.12% loss of activity), confirming that the A. terreus lipase is a serine hydrolase. The lipase was highly active on pig fat (151% relative activity) and groundnut oil (103% relative activity) and least active on kusum oil (18% relative activity). Extensive dialysis did not affect enzyme activity up to 168 h, suggesting the absence of any dialysable cofactor in the enzyme. The A. terreus lipase retained significant activity on freeze-drying and had a shelf-life of more than 6 months at room temperature. The A. terreus lipase exhibited 1,3-regiospecificity and was stable in various organic solvents.

Lipase production by Aspergillus and Penicillium species.

Forty each of aspergilli and penicillia were screened for extracellular lipase production on agar plates and in liquid medium containing olive oil as substrate. Twenty-nine aspergilli and twenty-six penicillia produced lipase. Out of these, 19 aspergilli and 22 penicillia showed activity both on Nile blue sulfate and glycerol tributyrate agar plates while only 10 aspergilli and 4 penicillia showed a positive response to glycerol tributyrate agar alone. The screening revealed 11 Aspergillus spp. and 15 Penicillium spp. as new lipase producers. Pig fat as an economic substrate for lipase production was also investigated.

Microbial lipases: production and applications.

Lipases occupy a prominent place among biocatalysts and have a wide spectrum of biotechnological applications. Lipases are unique as they hydrolyse fats into fatty acids and glycerol at the water-lipid interface and can reverse the reaction in non-aqueous media. The stability of these enzymes in organic solvents have pushed them into the frontier areas of organic synthesis leading to the designing of novel drugs, surfactants, bioactive compounds and oleochemicals. In addition, lipase-catalysed trans-esterification and inter-esterification reactions have been exploited in the fat industry. Looking into the wide scenario of lipase applications, commercialization of lipase production is a prime area of interest for microbiologists, process engineers and biochemists. Research carried out in this field has revealed that microbes, especially fungi and bacteria, are the tools of choice for commercial production. Recently, the structure determination of a few microbial lipases has widened our knowledge about the unique mechanism of catalysis of this enzyme.