Phytochemical analysis and biological investigation of Cheilanthes tenuifolia (Burm.f.) Swartz

Introduction: Cheilanthes tenuifolia is an evergreen ornamental small fern, belonging to the family Pteridaceae, that grows in warm and rocky regions worldwide. Many species of Cheilanthes genus are evidently endowed with important phytochemicals and bioactivities. This study aimed to perform a preliminary phytochemical analysis of Cheilanthes tenuifolia leaves alongside an evaluation of free radical scavenging, anti-inflammatory, antimicrobial, and clot lysis activities of extract fractions. Materials and methods: A preliminary phytochemical analysis was done after fractionation of ethanolic extract (ECT) with n-hexane (HCT) and chloroform (CCT). Then, 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, egg albumin and RBC membrane stabilization tests, disc diffusion, and human blood clot lysis assays were performed. Results: Phytochemical investigations suggested that the plant is rich in alkaloids, glycosides, tannins, and flavonoids. All obtained fractions exhibited concentration-dependent radical scavenging, inhibition of egg protein denaturation and RBC membrane lysis capacities. Except for antifungal tests, ECT exhibited better DPPH radical scavenging, anti-inflammatory, antibacterial, and clot lysis capacities than HCT and CCT fractions. However, all fractions exhibited a mild anti-inflammatory activity. Conclusion: C. tenuifolia might be a good source of antioxidant, anti-microbial, and anti-atherothrombotic agents. Further studies are required to isolate and characterize the active principles liable for each bioactivity, along with possible molecular interactions.

Evaluating a Dual-Ion Battery with an Antimony-Carbon Composite Anode

Dual-ion batteries (DIBs) are attracting attention due to their high operating voltage and promise in stationary energy storage applications. Among various anode materials, elements that alloy and dealloy with lithium are assumed to be prospective in bringing higher capacities and increasing the energy density of DIBs. In this work, antimony in the form of a composite with carbon (Sb-C) is evaluated as an anode material for DIB full cells for the first time. The behaviour of graphite||Sb-C cells is assessed in highly concentrated electrolytes in the absence and presence of an electrolyte additive (1 % vinylene carbonate) and in two cell voltage windows (2-4.5 V and 2-4.8 V). Sb-C full cells possess maximum estimated specific energies of 290 Wh/kg (based on electrode masses) and 154 Wh/kg (based on the combined mass of electrodes and active salt). The work expands the knowledge on the operation of DIBs with non-graphitic anodes.

Status of Serum Magnesium and Uric Acid in Patients with Chronic Obstructive Pulmonary Disease

Chronic obstructive pulmonary disease (COPD) remains a major public health problem with relatively high prevalence rates worldwide (5.0-13.0%). COPD is a major cause of morbidity and mortality worldwide and results in an economic and social burden that is both substantial and increasing. The purpose of the study was to explore the relationship of biochemical alterations of serum magnesium and uric acid with frequent exacerbations, hypoxia, increase hospital stay, morbidity and mortality in patients with COPD. This cross-sectional study was carried out in the Department of Biochemistry, Mymensingh Medical College, Bangladesh from January 2021 to December 2021. Data was collected from Medicine Department of Mymensingh Medical College Hospital, Bangladesh. A total number of 120 subjects participated in this study. Out of them, 60 apparently normal healthy individuals were selected as Group I and another 60 diagnosed COPD patients were selected as Group II. The results were calculated and analyzed by using statistical package for social science (SPSS), windows package version 21.0. Serum magnesium was measured by photoelectric colorimetric method using the test kit and serum uric acid was measured by enzymatic colorimetric method using the test kit. Data were expressed in mean±SD and statistical significance of different parameter was done by Pearson's correlation co-efficient test. The mean±SD values of serum magnesium were 2.15±0.29mg/dl and 1.54±0.30mg/dl in Group I and Group II respectively. Result was statistically highly significant (p<0.001). The mean±SD values of serum uric acid were 5.43±2.05mg/dl and 6.86±1.61mg/dl in Group I and Group II respectively. Result was statistically highly significant (p<0.001). Pearson's correlation coefficient test showed that there was significant (p=0.001) negative correlation (r= -0.415) found between serum magnesium and serum uric acid in study group. In this study, the result suggested that there was significant relation between COPD exacerbations and alteration of these biochemical parameters. So, by this study we recommended that routine evaluation of these parameters is important for prevention of exacerbations, reduction of morbidity and mortality in patients with COPD.

Study of Serum Zinc Level in Patients with Type 2 Diabetes Mellitus

A major global public health concern is the prevalence of diabetes mellitus, especially in developing countries like Bangladesh. While still battling communicable diseases, Bangladesh is already inundated with non-communicable diseases. Type 2 diabetes has been found in almost 90.0% of all instances of diabetes. The main risk factors for type 2 diabetes are an excessively caloric diet, advanced age, sedentary behavior and obesity. Along with preexisting risk factors, many micro-nutrients have been related to a rise in the incidence of diabetes. The study's objective was to measure and contrast the zinc levels in serum between individuals with type 2 diabetes mellitus and healthy controls. This cross-sectional study was conducted from July 2018 to June 2019 at the Mymensingh Medical College, Mymensingh, Bangladesh. Based on inclusion and exclusion criteria, the subjects were chosen using a purposeful (non-random) sample method. In total, 100 people participated in this study. They were divided into two groups: 50 individuals who had been diagnosed with type 2 diabetes mellitus were chosen as cases and 50 individuals who appeared to be in generally excellent health were chosen as controls. For the analytical aims of this investigation, serum zinc levels were examined. All values were expressed as the mean SD. The statistical analyses were carried out using the Windows program statistics package for social science (SPSS). The statistical significance of the difference between the case and control groups was evaluated using the Student's unpaired 't' test. A thorough research revealed that type 2 diabetes mellitus patients had significantly lower mean serum zinc levels than healthy controls (case group was 110.96±13.60 and control group 130.18±9.95μg/dl). Cross-sectional research was used in this study. The current study's findings showed that type 2 diabetes mellitus patients had dramatically changed serum zinc levels. The study's hypothesis was verified as a result.

Relationship of Serum Creatinine Level in Heart Failure Patients in Bangladesh

Heart failure means that the heart is unable to pump blood around the body properly. It usually happens because the heart has become too weak or stuff. In collaboration with department of Cardiology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh this cross-sectional study from January to December 2018 was performed in the department of Biochemistry in Mymensingh Medical College, Mymensingh, Bangladesh. The aim of this study was to explore the relationship of serum creatinine in patients with heart failure (HF) for management purpose. In this study 120 subjects were included, where 60 patients of diagnosed HF acts as case group and 60 individuals were normal healthy acts as control group. Serum creatinine was determined by colorimetric method from each sample. Statistical analysis was performed by SPSS windows package, version 21. Among the study groups the mean serum creatinine levels were 2.20±0.87mg/dl and 0.92±0.26mg/dl in case and control group respectively. Analysis showed that the mean serum creatinine level was highly significantly (p<0.001) increased in HF patients in comparison to that of control group.

Study of Serum Calcium and Magnesium Levels in Type 2 Diabetes Mellitus Patients

The prevalence of diabetes mellitus is a significant global public health concern, particularly in emerging nations like Bangladesh. Bangladesh is already overrun with non-communicable diseases while still battling communicable diseases. About 90.0% of all cases of diabetes that have been diagnosed are type 2 diabetes. High calorie diet, age, sedentary lifestyle and obesity are the main risk factors for type 2 diabetes. Different micronutrients have been linked to an increased incidence of diabetes in addition to existing risk factors. The goal of the study was to assess the serum levels of calcium and magnesium in people with type 2 diabetes mellitus and compare them to those in healthy controls. This cross-sectional study was conducted from July 2018 to June 2019 at the Mymensingh Medical College, Mymensingh, Department of Biochemistry in cooperation with the Department of Endocrinology, Mymensingh Medical College Hospital, Mymensingh, Bangladesh. Purposive (non-random) sampling was used to pick the subjects based on inclusion and exclusion criteria. This study had 100 individuals in total. Out of them, 50 people with type 2 diabetes mellitus who had been diagnosed were chosen as cases, and another 50 people who appeared to be in generally good health were chosen as controls. Serum calcium and magnesium levels were measured for this study's analytical purposes. The mean±SD was used to express all values. The statistical package for social science (SPSS), a Windows application, was used to conduct the statistical analyses. Using the Student's unpaired 't' test, the statistical significance of the difference between the case and control groups was assessed. Following comprehensive analysis, it was discovered that type 2 diabetes mellitus patients had considerably lower mean serum calcium (in case group was 8.46±0.63 and control group 8.86±0.64mg/dl) and magnesium levels (in case group was 2.09±0.42 and control group 2.24±0.16mg/dl) than healthy controls. According to the results of the current investigation, patients with type 2 diabetes mellitus had significantly altered serum calcium and magnesium levels. As a result, the study's hypothesis was accepted.

HbA1c and Troponin-I Levels and Their Relationship in Patients with Acute Coronary Syndrome

Acute coronary syndrome is a growing public health concern. Diabetic patients are more vulnerable to develop acute coronary syndrome due to accelerated atherosclerosis. Acute coronary syndrome is common in diabetes mellitus and is a major cause of mortality and morbidity in these patients. Troponin-I is a biochemical marker for cardiac muscle injury. Elevated glycated hemoglobin (HbA1c) is also regarded as an independent risk factor for acute coronary syndrome in patients with diabetes mellitus.The aim of this study was to assess the relationship of HbA1c and Troponin-I level in patients with acute coronary syndrome. This cross-sectional study was conducted in the Department of Biochemistry, Dhaka Medical College, Dhaka, Bangladesh from July 2018 to June 2019. Total study subjects were ninety five of both gender selected from the admitted patients of the cardiology department of the National Institute of Cardiovascular Diseases (NICVD), Dhaka. Diagnosis of acute coronary syndrome was confirmed by cardiologist. Diagnosis of diabetes mellitus was confirmed by Random Blood Glucose (RBG) level. Study subjects were grouped, acute coronary syndrome with diabetes mellitus as Group A and acute coronary syndrome without diabetes mellitus as Group B. Baseline parameters was recorded in data collection sheet. HbA1c, Troponin-I level of all study subjects were analyzed and recorded. Mean age of the study subjects in Group A and Group B were 51.06 years and 51.66 years respectively. Male gender was predominant in both groups. Mean SBP and DBP were significantly higher in Group A than Group B. Mean HbA1c level of the study subjects in Group A was significantly higher than Group B (p=0.001). Mean Troponin-I level in Group A was also significantly higher than Group B (p=0.023). HbA1c and Troponin-I levels were positively correlated in Group A (r=0.471, p=0.001). The present study demonstrated significant positive correlation of HbA1c and Troponin-I level in diabetic patients with acute coronary syndrome.

Study of Changes in Serum Copper Level in Patients with Acute Myocardial Infarction

Acute myocardial infarction (AMI) commonly known as heart attack is defined pathologically as the irreversible death of myocardial cells caused by ischemia. Risk factors include high blood pressure, smoking, diabetes, lack of exercise, obesity, high blood cholesterol and excessive alcohol intake. The major cause of acute MI is coronary atherosclerosis with superimposed luminal thrombus, which accounts for more than 80% of all infarcts. Micronutrients and trace elements are very essential for normal functioning of the body. Even though they are required in very small amount, an alteration in the level of this element may lead to serious diseases like CAD and its consequences. The injury induced by reperfusion of the ischemic myocardium could result partially from the cytotoxic effects of oxygen free radicals. Copper is involved in several of the reactions in the protection from free radical damage. So, this study was designed to evaluate serum cupper level in AMI patients. This case-control study was conducted in the Department of Biochemistry, Mymensingh Medical College, Mymensingh, Bangladesh from July 2016 to June 2017. Total number of subjects was 120 in number. Among them 60 were diagnosed case of acute myocardial infarction and 60 were apparently healthy volunteers. Data were collected using pre-designed data collection sheets. After proper counseling informed written consent was taken from the study population. The study revealed that mean serum copper level was higher in case group as compared to control group. The mean±SD values of copper were 105.44±24.15μg/dl and 146.49±23.52μg/dl in control and case group respectively. The level of significance was 0.001 (p<0.05). After analyzing the results of the study it is concluded that serum copper level was significantly higher in Acute Myocardial Infarction patients than normal individuals. Therefore, estimation of serum copper level in AMI patients might be useful to take appropriate measure to prevent free radical induced reperfusion injury.

Artificial intelligence-enabled rapid and symptom-based medication recommendation system (COV-MED) for the COVID-19 patients

In a general COVID-19 population in Cox’s Bazar, Bangladesh, we developed a medication recommendation system based on clinical information from the electronic medical record (EMR). Our goal was also to enable deep learning (DL) strategies to quickly assist physicians and COVID-19 patients by recommending necessary medications. The general demographic data, clinical symptoms, basic clinical tests, and drug information of 8953 patients were used to create a dataset. The learning model in this COVID-MED model was created using Keras (an open-source artificial neural network library) to solve regression problems. In this study, a sequential model was adopted. In order to improve the prediction capability and achieve global minima quickly and smoothly, the COVID-MED model incorporates an adaptive optimizer dubbed Adam. The model calculated a mean absolute error of 0.0037, a mean squared error of 0.000035, and a root mean squared error of 0.0059. The model predicts the output medications, such as injections or other oral medications, with around 99% accuracy. These findings show that medication can be predicted using information from the EMR. Similar models allow for patient-specific decision support to help prevent medication errors in diseases other than COVID-19.

Evaluation of Liver Function Tests in β-Thalassemia Major Children

Thalassemia is the most prevalent single gene defect in human beings worldwide. Repeated blood transfusions along with chelation therapy are mainstay of treatment in thalassemia patients. However these recurrent blood transfusions result in iron overload which along with chelation therapy causes deterioration of liver function. Aim of the study was to evaluate the liver function tests in β-thalassemia major patients. This cross sectional study was conducted in the Department of Biochemistry, Dhaka Medical College, Dhaka, Bangladesh from January 2017 to December 2017. In this study, 50 diagnosed patients of β Thalassemia major (Group A) and 50 apparently healthy children (Group B) of both sexes were selected from the department of Paediatrics, Dhaka medical college. The study parameters were serum ferritin, bilirubin, AST, ALT, ALP. The results were compared statistically between groups. Serum ferritin level (mean±SD) in thalassemic major patients in Group A (890±446.38 microgram/L) which is significantly higher above normal level. Serum bilirubin in Group A (3.27±2.62 mg/dl) and in Group B (0.48±0.24 mg/dl), Serum ALT in Group A (53.06±34.0 U/L) and in Group B (16.70±4.81 U/L), AST in Group A (84.56±33.54 U/L) and in Group B (11.60±2.72 U/L) and ALP levels in Group A (422.42±226.99 IU/L) and in Group B (221.86±80.54 IU/L). All the values were significantly higher (p<0.001) in β-thalassemia patient than that of normal children. This study concludes that liver function parameters are significantly higher in β thalassemia major patients. So routine evaluation of liver function tests may be advocated for thalassemic patients to predict early onset of hepatic dysfunction.

Advanced Dual-Ion Batteries with High-Capacity Negative Electrodes Incorporating Black Phosphorus

Dual-graphite batteries (DGBs), being an all-graphite-electrode variation of dual-ion batteries (DIBs), have attracted great attention in recent years as a possible low-cost technology for stationary energy storage due to the utilization of inexpensive graphite as a positive electrode (cathode) material. However, DGBs suffer from a low specific energy limited by the capacity of both electrode materials. In this work, a composite of black phosphorus with carbon (BP-C) is introduced as negative electrode (anode) material for DIB full-cells for the first time. The electrochemical behavior of the graphite || BP-C DIB cells is then discussed in the context of DGBs and DIBs using alloying anodes. Mechanistic studies confirm the staging behavior for anion storage in the graphite positive electrode and the formation of lithiated phosphorus alloys in the negative electrode. BP-C containing full-cells demonstrate promising electrochemical performance with specific energies of up to 319 Wh kg^-1 (related to masses of both electrode active materials) or 155 Wh kg^-1 (related to masses of electrode active materials and active salt), and high Coulombic efficiency. This work provides highly relevant insights for the development of advanced high-energy and safe DIBs incorporating BP-C and other high-capacity alloying materials in their anodes.

Impact of the COVID-19 pandemic on dental and medical education in Bangladesh: a pilot study and the implications

Objective: Lockdown and other measures, including the closure of universities, introduced by Governments across countries in response to the COVID-19 pandemic have appreciably impacted on the education of dental and medical students across countries. Key challenges included the need to rapidly move to e-learning as well as instigate new approaches to practicals for health science students. This involves lecturers and students necessarily needing to rapidly adapt to e-learning and other approaches. There have also been affordability issues among students to regularly access the Internet, and purchase the necessary equipment, particularly among those from low- and middle-income countries such as Bangladesh. Consequently, there is an urgent need to assess current challenges among senior level physicians and educators in Bangladesh regarding the education of dental and medical students arising from the current pandemic, and how these are being addressed, to provide future direction. This is particularly important in Bangladesh with high rates of both infectious and non-infectious diseases. Materials and Methods: Pragmatic investigation involving a purposely developed questionnaire based on previous studies and the experience of the co-authors. The questionnaire was distributed to 15 senior-level educators with the findings analysed by themes. Results: Key issues included little experience with e-learning at the start of the pandemic among both staff and students, poor internet access and cost of internet bundles. In addition, fear and anxieties among both students and staff. The colleges responded by instigating teaching classes for educators on e-learning and providing adequate personal protective equipment for staff and students during teaching and practical sessions. These formed the basis of future recommendations. Other recommendations included increased flexibility among staff and students. Conclusion: The pandemic posed appreciable challenges to both staff and students attending dental and medical colleges in Bangladesh. Some of the key issues are starting to be addressed. Bangladesh Journal of Medical Science Vol. 21 No. 02 April’22 Page : 444-454

Sensitivity Study of Type-I X-ray Bursts to Nuclear Reaction Rates

Type-I X-ray bursts are frequently occurring thermonuclear runaways on the surface of an accreting neutron star. The different nuclear reactions that empower the cataclysmic event play a key role in accurately comparing theoretical models and observations. We investigate the effect of the uncertainties in the nuclear reactions using a ONEZONE model for a set of different compositions and accretion rates that are within the range of the standard observed burst sources. A combination of a full-reaction network and a semi-analytic model is used to obtain the conditions at the time of X-ray burst ignition via simulating the settling process of the accreted material. We then evaluate the sensitivity of the X-ray burst model by varying the proton and alpha-induced reaction rates in JINA REACLIBV2.2 within representative nuclear physics uncertainties.

Preliminary Phytochemical Screening and Assessment of Pharmacological Activities of Leaves and Stems of Gynura procumbens (Lour.) Merr

The present study was designed to evaluate the preliminary phytochemical profiles and pharmmacological activities of different extractives (methanol and chloroform) of the leaves and stems of Gynura procumbens (Lour.) Merr. Preliminary phytochemical screenings demonstrated the presence of alkaloids, glycosides, steroids, flavonoids, tannins, saponins, gums and amides and reducing sugar in leaves and stems. Significant α-amylase inhibitory activities were found by the methanol (66.67%) and chloroform (70.63%) extracts of leaves of G. procumbens as compared to the standard drug acarbose (95.45%) at a concentration of 400 μg/ml. In the castor oil-induced diarrhea, the maximum inhibition of defecation was found by the chloroform fraction. During the anxiolytic activity test which was performed by open field and hole cross method, different extractives of leaves and stems of G. procumbens (500 mg/kg bw) reduced the total count of square crossed and hole crossed to a considerable extent in comparison to the control groups. In antipyretic assay, both extracts reduced the temperature to a significant extent in comparison to the standard group. Bangladesh Pharmaceutical Journal 22(1): 79-84, 2019

K-ion and Na-ion storage performances of Co3O4-Fe2O3 nanoparticle-decorated super P carbon black prepared by a ball milling process

The hybridisation of Co₃O₄ and Fe₂O₃ nanoparticles dispersed in a super P carbon matrix is proposed as a favourable approach to improve the electrochemical performance (reversible capacity, cycling stability and rate capability) of the metal oxide electrodes in metal-ion batteries. Hybrid Co₃O₄-Fe₂O₃/C is prepared by a simple, cheap and easily scalable molten salt method combined with ball-milling and used in sodium-ion and potassium-ion batteries for the first time. The electrode exhibits excellent cycling stability and superior rate capability in sodium-ion cells with a capacity recovery of 440 mA h g^-1 (93% retention) after 180 long-term cycles at 50-1000 mA g^-1 and back to 50 mA g^-1. In contrast, Co₃O₄-Fe₂O₃, Co₃O₄ and Fe₂O₃ electrodes display unsatisfactory electrochemical performance. The hybrid Co₃O₄-Fe₂O₃/C is also reactive with potassium and capable of delivering a reversible capacity of 220 mA h g^-1 at 50 mA g^-1 which is comparable with the most reported anode materials for potassium-ion batteries. The obtained results broaden the range of transition metal oxide-based hybrids as potential anodes for K-ion and Na-ion batteries, and suggest that further studies of these materials with potassium and sodium are worthwhile.

Nanocrystalline SnS2coated onto reduced graphene oxide: demonstrating the feasibility of a non-graphitic anode with sulfide chemistry for potassium-ion batteries

An anode material incorporating a high capacity sulfide compound is reported for potassium-ion batteries.

Tin-based composite anodes for potassium-ion batteries

An anode based on the tetragonal tin (Sn) phase that can alloy electrochemically with potassium is demonstrated for potassium-ion batteries.

Pigtail Catheter in the Management of Liver Abscess

Amoebic liver abscess is a common condition in Bangladesh. Though conservative treatment plays a major role, refractory patients can be successfully treated with minimally invasive approach. This prospective study was carried out to evaluate the prospect of sono-guided percutaneous catheter drainage for liver abscess patients not responding to conservative treatment. This study was done at Dhaka Medical College Hospital from January 2005 to June 2006 among patients with liver abscess that were treated conservatively outside and got admitted in different surgery and medicine units. Included 35 patients were evaluated clinically and through relevant investigations. Sono-guided percutaneous pigtail catheter was introduced for drainage and patients were followed up for two weeks on average at hospital indoor by amount of drainage, clinical improvement and serial follow up USG. After discharge from the hospital, all patients were followed up monthly and assessed clinically and ultrasonographically up to two months on outdoor basis. Thirty five patients underwent pigtail catheter drainage that was refractory to conservative treatment or needle aspiration. Following insertion of catheter patients who were pyrexic, fever subsided in two to three days and never back during the postoperative period and follow up. Antimicrobials were changed according to the report of the culture and sensitivity of the aspirate that was done routinely. Maximum total (4300 ml) amount of pus was drained in a patient. Average duration of catheter drainage in this study was 8 days. With a very low morbidity and zero mortality rates, minimum treatment costs and early return to regular life style proved this minimally invasive procedure to be a rational treatment option for amoebic liver abscess in selective cases.

Understanding Structure-Function Relationship in Hybrid Co3O4-Fe2O3/C Lithium-Ion Battery Electrodes

A range of high-capacity Li-ion anode materials (conversion reactions with lithium) suffer from poor cycling stability and limited high-rate performance. These issues can be addressed through hybridization of multiple nanostructured components in an electrode. Using a Co3O4-Fe2O3/C system as an example, we demonstrate that the cycling stability and rate performance are improved in a hybrid electrode. The hybrid Co3O4-Fe2O3/C electrode exhibits long-term cycling stability (300 cycles) at a moderate current rate with a retained capacity of approximately 700 mAh g(-1). The reversible capacity of the Co3O4-Fe2O3/C electrode is still about 400 mAh g(-1) (above the theoretical capacity of graphite) at a high current rate of ca. 3 A g(-1), whereas Co3O4-Fe2O3, Fe2O3/C, and Co3O4/C electrodes (used as controls) are unable to operate as effectively under identical testing conditions. To understand the structure-function relationship in the hybrid electrode and the reasons for the enhanced cycling stability, we employed a combination of ex situ and in situ techniques. Our results indicate that the improvements in the hybrid electrode originate from the combination of sequential electrochemical activity of the transition metal oxides with an enhanced electronic conductivity provided by percolating carbon chains.

Ex situ electrochemical sodiation/desodiation observation of Co₃O₄ anchored carbon nanotubes: a high performance sodium-ion battery anode produced by pulsed plasma in a liquid

Liquid plasma, produced by nanosecond pulses, provides an efficient and simple way to fabricate a nanocomposite architecture of Co3O4/CNTs from carbon nanotubes (CNTs) and clusters of Co3O4 nanoparticles in deionized water. The crucial feature of the composite's structure is that Co3O4 nanoparticle clusters are uniformly dispersed and anchored to CNT networks in which Co3O4 guarantees high electrochemical reactivity towards sodium, and CNTs provide conductivity and stabilize the anode structure. We demonstrated that the Co3O4/CNT nanocomposite is capable of delivering a stable and high capacity of 403 mA h g(-1) at 50 mA g(-1) after 100 cycles where the sodium uptake/extract is confirmed in the way of reversible conversion reaction by adopting ex situ techniques. The rate capability of the composite is significantly improved and its reversible capacity is measured to be 212 mA h g(-1) at 1.6 A g(-1) and 190 mA h g(-1) at 3.2 A g(-1), respectively. Due to the simple synthesis technique with high electrochemical performance, Co3O4/CNT nanocomposites have great potential as anode materials for sodium-ion batteries.

Benzylidene anabaseines act as high-affinity agonists for insect nicotinic acetylcholine receptors

Benzylidene anabaseines are agonists selective for vertebrate alpha7-nicotinic acetylcholine receptor (nAChR), while they exhibit antagonist activity toward vertebrate alpha4beta2-nAChR. To investigate the effects of benzylidene anabaseines on insect nAChRs, we performed [3H]epibatidine-binding assays and neurophysiological experiments using American cockroach (Periplaneta americana) nerve-cord preparations. Of the six compounds tested, 3-benzylideneanabaseine (BA) and 6'-chloro-3-benzylideneanabaseine (CBA) displayed the highest potency in the binding assays, with K(i)s of 35.0 and 21.2nM, respectively. The introduction of a nitro group at the 4-position of the phenyl group led to a decrease in affinity by two orders of magnitude, while that of a chlorine atom at the 6'-position had little effect on affinity. In neurophysiological experiments, BA at 3.3 microg/ml increased the spike frequency observed with the nerve preparation, as observed with nicotine at 16.6 microg/ml. These findings suggest that benzylidene anabaseines act as high-affinity agonists in P. americana nAChRs and that they might therefore prove useful as probes for insect nAChRs.

Spasmolytic constituents from Eucalyptus camaldulensis var. obtusa leaves

Phytochemical studies on the leaves of Eucalyptus camaldulensis var. obtusa have resulted in the isolation of a new triterpenoid camaldulin (3beta-formyloxyurs-11-en-28,13beta-olide) (1) along with ursolic acid lactone acetate (2), ursolic acid lactone (3), betulinic acid (4), and beta-sitosterol 3-O-beta-D-glucopyranoside (5). The structures were assigned on the basis of 1D and 2D NMR studies. Compounds 1-3 were tested for spasmolytic activity and were found to possess calcium antagonist activity.

Triterpenoidal constituents from Eucalyptus camaldulensis var. obtusa leaves

An investigation on the constituents of the fresh, uncrushed leaves of Ecalyptus camaldulensis var. obtusa has led to the isolation of the triterpenoid amirinic acid and four known triterpenoids ursolic acid lactone, betulinic acid, oleanolic acid and ursolic acid. Amirinic acid transformed into amirolide in deuterated chloroform at room temperature. The new products were characterized by exhaustive spectroscopic studies as 2alpha,3beta,7beta-trihydroxy-11alpha-methoxyurs -12-en-28-oic acid and 2alpha,3beta,7beta-trihydroxyurs-11-en-28,13beta -olide.

Detection of HIV-antibody evaluation of four commercially available enzyme immunoassays

We evaluated 550 serum samples with four commercially available enzyme immunoassays and Western Blot was used as the confirmatory test for antibodies against human immunodeficiency virus (HIV). The Wellcozyme (Wellcome), Flow HIV-TEK G, and Behring test kits identified all 50 Western Blot positive samples correctly, whereas DuPont failed to detect one sample. None of the kit was able to pickup one sample that showed a faint P24 band on Western Blot strip. The frequency of false positive reaction in the 500 negative serum samples were Wellcome 0%, Behring and DuPont 0.2% and Flow HIV-TEK 0.4%.