Synthesis and antimicrobial activity of 4-substituted thiazol-2-yl hydrazine derivatives of 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carbaldehyde

The manuscript reports synthesis and antimicrobial activity of several novel heterocyclic compounds in which 1,4-disubstituted 1,2,3-triazole synthesized via click chemistry approach and 4-aryl (5a-h) and 4-piperazinyl amide (7a-e) or 4-aryl amide (8a-e) substituted thiazole rings, are bridged through hydrazine linkage. Structures of all the synthesized compounds have been elucidated using 1H and 13C NMR and mass spectral analysis. In vitro antimicrobial screening of the target compounds has been carried out against six bacterial species viz. E. coli, P. aeruginosa, B. subtilis, S. pyogenes, K. pneumoniae and S. aureus and four fungal species viz. C. albicans, T. viride, A. flavus and A. brasiliensis. The activity study revealed that many of the compounds possess moderate to good activity against the tested microorganisms. The active compounds have been further studied to determine the minimum inhibitory concentration (MIC)

Synthesis and antimicrobial activity of 4-substituted thiazol-2-yl hydrazine derivatives of 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carbaldehyde

716-723The manuscript reports synthesis and antimicrobial activity of several novel heterocyclic compounds in which 1,4-disubstituted 1,2,3-triazole synthesized via click chemistry approach and 4-aryl (5a-h) and 4-piperazinyl amide (7a-e) or 4-aryl amide (8a-e) substituted thiazole rings, are bridged through hydrazine linkage. Structures of all the synthesized compounds have been elucidated using 1H and 13C NMR and mass spectral analysis. In vitro antimicrobial screening of the target compounds has been carried out against six bacterial species viz. E. coli, P. aeruginosa, B. subtilis, S. pyogenes, K. pneumoniae and S. aureus and four fungal species viz. C. albicans, T. viride, A. flavus and A. brasiliensis. The activity study revealed that many of the compounds possess moderate to good activity against the tested microorganisms. The active compounds have been further studied to determine the minimum inhibitory concentration (MIC)

Magnetic field enhancement technique in the fluid flow gap of a single coil twin tube Magnetorheological damper using magnetic shields

Smart dampers in the automobile suspension system bring a precise balance between the ride comfort and stability through a controllable damping coefficient. Energy absorbed by a Magnetorheological (MR) damper is a dependent function of flux density in the fluid flow gap. In this paper, magnetic field enhancement technique in the form of a single cylindrical shield and sandwich cylindrical shield is incorporated in a twin tube single coil MR damper. The field strength in different configurations of MR damper having various type of shield configuration is computationally investigated. Further, the effect of shield thickness on field strength is investigated. A significant overall improvement in the magnetic field strength is observed in the MR damper configuration having copper alloy shield

Rattusin, an intestinal a-defensin-related peptide in rats with a unique cysteine spacing pattern and salt-insensitive antibacterial activities

Cationic antimicrobial peptides are essential components of the innate immune system. As a major family of mammalian antimicrobial peptides, defensins are expressed mainly by mucosal epithelial cells and promyelocytes. Despite the capacity to kill a broad spectrum of bacteria through physical disruption of membranes, most defensins show substantially reduced antibacterial activities in the presence of monovalent and divalent cations, thereby limiting their therapeutic potential, particularly for the treatment of systemic infections. Genome-wide computational screening of the rat genome led to the identification of the gene for a novel a-defensin-related peptide that we termed rattusin. Rattusin shares a highly conserved signal and prosequence with mammalian a-defensins, but instead of the canonical a-defensin six-cysteine motif, rattusin consists of five cysteines with a distinctive spacing pattern. Furthermore, rattusin is preferentially expressed in Paneth cells of the distal small intestine with potent antibacterial activity against a broad range of Gram-negative and Gram-positive bacteria, including antibiotic-resistant strains. The MICs were mostly in the range of 2 to 4 uM, with no appreciable toxicity to mammalian cells at up to 100 uM. In contrast to classical a- and B-defensins, rattusin retained its activity in the presence of physiological concentrations of NaCl and Mg2+, making it an attractive antimicrobial candidate for both topical and systemic applications.Peer reviewedAnimal Scienc

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Synthesis and biological evaluation of a series of 1,4-disubstituted 1,2,3-triazole derivatives as possible antimicrobial agents

Three series of novel compounds derived from 1-(2,6-difluorobenzyl)-1H-1,2,3-triazole-4-carboxylic acid bearing piperazine carboxamides, (5-(substituted phenyl)-1,3,4-oxadiazol-2-yl) and (5-(alkylthio)-1,3,4-oxadiazol-2-yl) substitutions at the 4-position were synthesized. Synthesized compounds were characterized by 1H NMR, 13C NMR and mass spectral analysis and evaluated for their antimicrobial activities. Interestingly, most of the compounds exhibit moderate to good activities against tested Gram-positive, Gram-negative bacterial strains as well as fungal strains

Synthesis and biological activity of novel derivatives of 2-(5-(3-fluro-4-methoxy phenyl)-1H-pyrazol-3-yl)-5-aryl-1,3,4-oxadiazole

892-897A series of new 1,3,4-oxadiazole derivatives have been synthesized by condensation of 5-(3-fluro-4-methoxyphenyl)-1H-pyrazole-3-carbohydrazide with different substituted benzoic acids. All the synthesized compounds have been screened for antibacterial activity against S. aureus, E. coli, B. subtilis, P. aeruginosa, S. pyogenes, K. terrigena, K. Pneumoniae and antifungal activity against T. viride, A. flavus, A. brasillansis and C. albicans. Most of the synthesized compounds show good antimicrobial activity