Investigating purification and activity analysis of urease enzyme extracted from jack bean source: A green chemistry approach.

Urease is an enzyme of historical importance in the field of biochemistry, generally microbial and plant urease is the primary sources of urease. The significant applications of urease enzyme are found to be foremost in food industry, medical equipment's and biosensors. In this work, urease has been extracted from Jack bean meal using ammonium sulphate and acetone precipitation. A significant amount of urease was precipitated and concentrated at 60% saturated solution of ammonium sulphate. The obtained precipitates were dissolved in 50 mM phosphate buffer (pH 8) after centrifugation, and subjected to sodium dodecyl-sulphate polyacrylamide gel electrophoresis (SDS-PAGE) to determine the molecular weight of urease. Results obtained from the SDS-PAGE were validated using Zymography. Anion exchange chromatography was used to separate the desired protein at different pH (7.0, 7.5 and 8.0). The eluted fractions were assessed for urease activity using phenol-nitroprusside dependent ammonia release assay. Under these assay conditions, one unit of urease activity was calibrated as the amount of enzyme liberating 1 µM of NH3 from urea per unit time. The eluted fraction and Zymography analysis show the purified urease observed at 90 kDa and activity of purified urease, respectively. The obtained results for specific activity (173.67Units mg) and % purification (99.71%) for urease has been compared with the available literature, which are found to be in close relation with existing results. The proposed method is a novel approach which has recorded highest % purification and specific activity. Furthermore, it can be suitable for extracting urease from jack bean source for various industrial applications.

WCK 4034: A promising oxazolidinone for treating gram positive infections.

Increased resistance to gram positive infections have highlighted the limitations of currently available drug treatments including penicillins, macrolides and glycopeptides. As an alternative to address these challenges; Linezolid, the first antibiotic from oxazolidinone class, have shown the promising activities against such infections, although associated toxicological issues limiting the use of linezolid for prolonged treatments. In order to circumvent disadvantages allied with the marketed drugs, we herein reporting the synthesis of WCK 4034, an oxazolidinone antibiotic through our structure activity relationship (SAR) program. Through this exercise, WCK 4034, has shown competitive MIC values against Methicillin Sensitive S. aureus (MSSA, Sta-001), Methicillin Resistant S. aureus (MRSA, Sta-032), S. pneumoniae ATCC 49619 and H. influenza ATCC 35054 species as like linezolid. Although with an additional advantage; WCK 4034 has been found superior during dog PK studies as compare to Linezolid. With the preliminary studies in our hand, we herein assuming these improved pharmacokinetic values would be helpful. Moreover, WCK 4034 has successfully completed pre-clinical studies and ready to enter the clinical space, and paved the way for in house development of other oxazolidinone NCEs.

Multichannel DenseNet Architecture for Classification of Mammographic Breast Density for Breast Cancer Detection.

Percentage mammographic breast density (MBD) is one of the most notable biomarkers. It is assessed visually with the support of radiologists with the four qualitative Breast Imaging Reporting and Data System (BIRADS) categories. It is demanding for radiologists to differentiate between the two variably allocated BIRADS classes, namely, "BIRADS C and BIRADS D." Recently, convolution neural networks have been found superior in classification tasks due to their ability to extract local features with shared weight architecture and space invariance characteristics. The proposed study intends to examine an artificial intelligence (AI)-based MBD classifier toward developing a latent computer-assisted tool for radiologists to distinguish the BIRADS class in modern clinical progress. This article proposes a multichannel DenseNet architecture for MBD classification. The proposed architecture consists of four-channel DenseNet transfer learning architecture to extract significant features from a single patient's two a mediolateral oblique (MLO) and two craniocaudal (CC) views of digital mammograms. The performance of the proposed classifier is evaluated using 200 cases consisting of 800 digital mammograms of the different BIRADS density classes with validated density ground truth. The classifier's performance is assessed with quantitative metrics such as precision, responsiveness, specificity, and the area under the curve (AUC). The concluding preliminary outcomes reveal that this intended multichannel model has delivered good performance with an accuracy of 96.67% during training and 90.06% during testing and an average AUC of 0.9625. Obtained results are also validated qualitatively with the help of a radiologist expert in the field of MBD. Proposed architecture achieved state-of-the-art results with a fewer number of images and with less computation power.

Self-assembly of bovine serum albumin (BSA)-dextran bio-nanoconjugate: structural, antioxidant and in vitro wound healing studies.

Glycation of proteins is often considered as a method to improve their functional properties for promising applications in wound healing. Furthermore, a marked increase in percentage of radical scavenging activity of the conjugates makes it an effective antioxidant synthetic strategy. A simple conjugation process was employed to develop bovine serum albumin-dextran conjugates (BSA-dextran) using Maillard reaction. Higher electrophoretic mobility and surface charge in the prepared conjugates was observed in native PAGE electrophoresis and zeta potential. Moreover, the fluorescence, FTIR and Raman analysis of the BSA-dextran conjugates shows significant shift in the fluorescence and wavelength as a consequence of conjugate formation. In vitro wound healing assay showed increased cell proliferation and migration effect. These finding suggests that BSA-dextran conjugate could open up a new practical way for exploration in the area of wound healing.

Correction: Self-assembly of bovine serum albumin (BSA)-dextran bio-nanoconjugate: structural, antioxidant and in vitro wound healing studies.

[This corrects the article DOI: 10.1039/D0RA09301G.].

Complete Genome Sequence of Lactobacillus plantarum Strain JDARSH, Isolated from Sheep Milk.

Lactobacillus plantarum strain JDARSH, a potential probiotic with a wide range of functions, was isolated from sheep milk. Here, we report the whole-genome sequence of this bacterium. The draft genome yielded a 3.20-Mb genome and 2,980 protein-coding sequences.

Prevalence of occupational exposure to HIV and utilization of HIV post-exposure prophylaxis among health staff at Bule Hora General Hospital, Bule Hora, Ethiopia.

INTRODUCTION: occupational risk of HIV and low utilization of post-exposure prophylaxis (PEP) among nurses has become a global public health concern. According to the International Labor Organization estimates, 2.02 million people die each year from work-related accidents or diseases. More than 317 million people suffer, and there are an estimated 337 million fatal and non-fatal work-related accidents per year. WHO report indicates, more than 59 million health care workers around the world are exposed to biological hazards and about 10% of HIV among health workers is the result of needle stick injury. This study focused on assessing the prevalence of occupational exposure to HIV post-exposure prophylaxis among nurses at Bule Hora Hospital. METHODS: institutional based cross-sectional study design was conducted from March 2019 to April 2019. In this study, 306 study participants were involved in the study data was collected using a structured and semi-structured questionnaire. The cleaned data (edited) was entered into Epi-Data version 4.4.3.1 and exported to SPSS Statistics Version 20 for analysis. RESULTS: high incidence (61.6%) of occupational exposure to HIV was found in this study. The two leading types of exposure were blood splash 40.5% and needle stick 37.8% injury followed by giving injection 27% and uncooperativeness 21.6% subsequently. About 35.1% of nurses were found to be not using personal protective equipment's while being exposed to HIV infection while on work. CONCLUSION: occupational exposure to HIV is quite common among nurses in Bule Hora Hospital. Blood splash exposure and exposure to needle stick injury are believed to be the commonest types of workplace risks. Nearly 29.7% of nurses have no training on infection prevention and management while at work. Nearly 50% of the exposed nurses didn't report the incident to the concerned authorities. One fourth of the sources of exposure were unscreened and among the screened sources of exposure 42.9% were found to be HIV positive.

Hybrid chitosan-ZnO nanoparticles coated with a sonochemical technique on silk fibroin-PVA composite film: A synergistic antibacterial activity.

The hybrid chitosan-ZnO nanoparticles (C@ZnO NPs) are synthesized and coated on Silk fibroin-polyvinyl alcohol (SF-PVA) composite film by a sonochemical coating process. These are systematically studied for their synergistic antibacterial activity and reported. The coated composite films show the excellent antibacterial activity against Gram-positive and Gram-negative bacteria. The composite films are characterized by using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Scanning Electron Microscopy (SEM) studies. The specific surface area and porosity are studied by Brunauer-Emmett-Teller (BET) analysis under nitrogen gas adsorption. The swelling degree, mechanical property and cell viability study of coated and uncoated composite films are investigated. The results showed that the specific surface area, porosity, swelling degree, and mechanical property of coated composite films increased with increasing the concentrations of C@ZnO NPs on SF-PVA composite film. Cell viability study confirmed the cytocompatible nature of all the C@ZnO NPs coated composite films. Thus, obtained properties of composite films reveal the potential of this material which can be used as antibacterial wound dressing applications.

Surface-Modified Cobalt Ferrite Nanoparticles for Rapid Capture, Detection, and Removal of Pathogens: a Potential Material for Water Purification.

Enteric infections resulting from the consumption of contaminated drinking water, inadequate supply of water for personal hygiene, and poor sanitation take a heavy toll worldwide, and developing countries are the major sufferers. Consumption of microbiologically contaminated water leads to diseases such as amoebiasis, cholera, shigellosis, typhoid, and viral infections leading to gastroenteritis and hepatitis B. The present investigation deals with the development of effective method to capture and eliminate microbial contamination of water and improve the quality of water and thus decreasing the contaminated waterborne infections. Over the last decade, numerous biomedical applications have emerged for magnetic nanoparticles (MNPs) specifically iron oxide nanoparticles. For the first time, we have explored functionalized cobalt ferrite nanoparticles (NPs) for capture and detection of pathogens. The captured bacterial were separated by using simple magnet. To begin with, the prepared NPs were confirmed for biocompatibility study and further used for their ability to detect the bacteria in solution. For this, standard bacterial concentrations were prepared and used to confirm the ability of these particles to capture and detect the bacteria. The effect of particle concentration, time, and pH has been studied, and the respective results have been discussed. It is observed that the presence of amine group on the surface of NPs shows nonspecific affinity and capability to capture Escherichia coli and Staphylococcus aureus. The possible underlying mechanism is discussed in the present manuscript. Based upon this, the present material can be considered for large-scale bacteria capture in water purification application.

Photoinactivation of bacteria by using Fe-doped TiO2-MWCNTs nanocomposites.

In this study, nanocomposites of Fe-doped TiO2 with multi-walled carbon nanotubes (0.1- 0.5 wt. %) were prepared by using sol-gel method. The structural and morphological analysis were carried out with using X-ray diffraction pattern and transmission electron microscopy, which confirm the presence of pure anatase phase and particle sizes in the range 15-20 nm. X-ray photoelectron spectroscopy was used to determine the surface compositions of the nanocomposites. UV-vis diffuse reflectance spectra confirm redshift in the optical absorption edge of nanocomposites with increasing amount of multi-walled carbon nanotubes. Nanocomposites show photoinactivation against gram-positive Bacillus subtilis as well as gram-negative Pseudomonas aeruginosa. Fe-TiO2-multi-walled carbon nanotubes (0.5 wt. %) nanocomposites show higher photoinactivation capability as compared with other nanocomposites. The photoluminescence study reveals that the Fe-TiO2-multi-walled carbon nanotubes nanocomposites are capable to generate higher rate of reactive oxygen species species than that of other nanocomposites. Our experimental results demonstrated that the Fe-TiO2-multi-walled carbon nanotubes nanocomposites act as efficient antibacterial agents against a wide range of microorganisms to prevent and control the persistence and spreading of bacterial infections.

Enhanced photocatalytic inactivation of bacteria on Fe-containing TiO2 nanoparticles under fluorescent light.

In this paper, the photocatalytic activity of Fe-TiO2 nanoparticles (NPs) under fluorescent light was studied using Escherichia coli and Staphylococcus aureus. Fe-TiO2 NPs were synthesized using a sol-gel method and characterized with X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV-visible diffuse reflectance spectroscopy (UV-vis DRS) and transmission electron microscopy. The efficiency of photocatalytic inactivation towards E. coli was studied under different physicochemical parameters. The photocatalytic inactivation rate increased with increasing Fe content in TiO2 NPs and the highest inactivation was achieved for 3.0 mol% Fe-TiO2 NPs under fluorescent light. These results demonstrate that the presence of an optimum concentration of Fe in TiO2 matrix enhances the photocatalytic inactivation of TiO2 NPs under fluorescent light.

Innovative Developments in Bacterial Detection with Magnetic Nanoparticles.

It has been seen from the last decade that many bacterial strains are becoming insensitive to conventional detection techniques and it has its own limitations. Current developments in nanoscience and nanotechnology have expanded the ability to design and construct nanomaterials with targeting, therapeutic, and diagnostic functions. These multifunctional nanomaterials have attracted researchers, to be used as the promising tool for selective bacterial sensing applications. An important advantage of using magnetic nanoparticles to capture bacteria is the simple separation of bacteria from biological samples using magnets. This review includes significance of magnetic nanoparticles in bacterial detection. Relevant to topic, properties, designing strategies for magnetic nanoparticle, and innovative techniques used for detection are discussed. This review provides the readers how magnetic properties of nanoparticles can be utilized systematically for bacterial identification.

Synthesis and anti-inflammatory activity of some new 4,5-dihydro-1,5-diaryl-1H-pyrazole-3-substituted-heteroazole derivatives.

A series of 4,5-dihydro-1,5-diaryl-1H-pyrazole-3-substituted-heteroazoles were designed and synthesized in order to obtain new compounds with potential anti-inflammatory activity. The title compounds were screened for in vivo anti-inflammatory activity by using Carrageenan induced rat paw edema method. Diclofenac sodium was used as a standard drug for comparison. Out of the 30 compounds tested, compound 19a, 19b, 25a, 25b exhibited significant anti-inflammatory activity. Selected compounds were also screened for in vitro COX-2 inhibition assay and analgesic activity in the acetic acid induced writhing model.

Synthesis of novel bioactive derivatives of 3-(4-chlorophenyl)-2-hydrazino-5,6,7,8-tetrahydrobenzo(b)thieno[2,3-d]pyrimidine-4(3H)-ones.

A series of triazolo[4,3-a]tetrahydrobenzo(b)thieno[3,2-e]pyrimidine-5(4H)-ones (12a-n) were synthesized and evaluated for CNS depressant, skeletal muscle relaxant and anticonvulsant activities by photoactometer, Rotarod and pentylenetetrazole induced the convulsions method respectively in Swiss albino mice. Diazepam was used as standard drug. The five derivatives 12b, 12c, 12d, 12i and 12m showed the CNS depressant and skeletal muscle relaxant activities comparable to those of diazepam at a dose of 5mg/kg. These derivatives also exhibited good activity when tested for anticonvulsant activity in mice at different dose levels. The ED(50) values for these derivatives are in the range of 4.40-9.33 mg/kg.