The Transportation of Maxwell Fluid in the Rotating and Stretching System: Rotor-Stator Spinning Disc Reactor Applications

We have developed a mathematical model and obtained a numerical solution for the motion of a non-Newtonian Maxwell fluid between two disks having rotation and stretching velocity with convective boundary constraints, porous medium and thermal radiation. The present Maxwell fluid flow model with specified boundary constraints is not discussed so far. The proposed model has a lot of applications in electrical power generation, nuclear energy plants, astrophysical flows, space vehicles, geothermal extractions, and spinning disc reactor. The Von Karman similarity approach is used for the solution and validation of the solution is also provided. The solution is obtained numerically with finite difference method (FDM) based ND-solve command in Mathematica software. The effects of magnetic field, porous medium, radiation parameter, Deborah number, Prandtl number, and Reynolds number on skin friction, heat transfer, flow and temperature fields are discussed in detail. Due to the significant void fraction in the medium, porosity parameter shows unique trend compared to other parameters for the radial velocity profile. It has tendency to enhance the radial velocity near both the disc but in the middle part of system, porosity parameter retards radial velocity significantly.

Recent updates on structural insights of MAO-B inhibitors: a review on target-based approach

Parkinson's disease is a neurodegenerative disorder characterized by slow movement, tremors, and stiffness caused due to loss of dopaminergic neurons caused in the brain's substantia nigra. The concentration of dopamine is decreased in the brain. Parkinson's disease may be happened because of various genetic and environmental factors. Parkinson's disease is related to the irregular expression of the monoamine oxidase (MAO) enzyme, precisely type B, which causes the oxidative deamination of biogenic amines such as dopamine. MAO-B inhibitors, available currently in the market, carry various adverse effects such as dizziness, nausea, vomiting, lightheadedness, fainting, etc. So, there is an urgent need to develop new MAO-B inhibitors with minimum side effects. In this review, we have included recently studied compounds (2018 onwards). Agrawal et al. reported MAO-B inhibitors with IC₅₀ 0.0051 µM and showed good binding affinity. Enriquez et al. reported a compound with IC₅₀ 144 nM and bind with some critical amino acid residue Tyr60, Ile198, and Ile199. This article also describes the structure-activity relationship of the compounds and clinical trial studies of related derivatives. These compounds may be used as lead compounds to develop potent compounds as MAO-B inhibitors.

Evaluation of gingival displacement, bleeding and ease of application for polytetrafluoroethylene (PTFE) and conventional retraction cord - a clinical trial

OBJECTIVE

Conventional use of retraction cord in soft tissue management is effective only when the non-resilient nature of material does not jeopardize gingival health. Therefore this study aims to clinically evaluate the gingival displacement, ease of application and bleeding from polytetrafluoroethylene (PTFE) retraction cord.

PATIENTS AND METHODS

This study is a single-center, parallel-group, randomized controlled clinical trial (1:1). Sixty patients indicated for full coverage metal-ceramic restoration for first molars were enrolled and randomly allocated to experimental (PTFE Cord) and control (conventional plain retraction cord) groups. After crown preparation and isolation, a pre-displacement impression was made. Assigned gingival displacement material was applied for 5 minutes, followed by post-displacement impression. Casts were prepared and used for assessment of mean horizontal gingival displacement by measuring displacement using a stereomicroscope (20 x). Post-displacement gingival bleeding and ease of application were also assessed clinically. t-test and Chi-square tests were used for statistical assessment of gingival displacement, gingival bleeding and ease of application.

RESULTS

Gingival displacement, bleeding and ease of application were similar among study groups (p > 0.05). Mean gingival displacement in the experimental group was 197.1 µm, and 167.7 µm in the control group. Bleeding was observed in 30% and 20% of cases of experimental and control group, respectively. Ease of application was 'difficult' in 53.3% and 43.3% of cases of experimental and control group, respectively. Non-impregnated gingival retraction cord and PTFE cord displayed similar outcomes of gingival displacement, ease of placement and bleeding after cord removal.

CONCLUSIONS

Post-displacement bleeding and discomfort for PTFE cord placement suggest that this technique needs improvement. Therefore further studies are warranted to improve and investigate the physical and biological response to PTFE retraction cord.

Impact of Thread-Based Microfluidic Devices in Modern Analysis: An Update on Recent Trends and Applications

Background:

Inexpensive and disposable microfluidic sensing equipment is in strong demand which can detect biomarkers of diseases found in urine or blood. From recent studies, it has been found that multifilament threads can be used for producing low-cost microfluidic devices hence these multifilament threads act as an inexpensive alternative. Thread has various advantages to make it appropriate to be used in microfluidics-based technologies which include its low price, lightweight, easy availability, and hydrophilic nature. The use of any external pumping system is avoided by the presence of capillary channels in threads which allows the easy flow of fluid. Since thread offers more choices of materials over paper and also paper-based microfluidics preparation is expensive therefore thread-based microfluidic sensor has been considered more advantageous over paper-based microfluidic sensors.

Methods:

Various research reports were collected from search engines like ScienceDirect, Pub-med, ResearchGate, and Google Scholar. Further important outcomes from these reports along with basic experimental setup details have been compiled under different sections of this manuscript.

Conclusion:

Non-invasive or blood-free diagnosis can reduce the pain and several risk factors compared with the traditional invasive diagnosis so it is gaining more attention regarding health status monitoring. The various applications regarding thread-based devices include the detection of glucose and its determination, diagnosis of diabetes and kidney failure simultaneously, food dyes separation, sweat pH and lactate determination, selective potassium analysis, multiple antibodies detections, an assay of microbes, for acid-base titrations, as ELISA’s platform, diagnosis of infectious diseases, ion sensing, identification of blood types and detection of bio-samples, etc.

p53 as a potential target for treatment of cancer: A perspective on recent advancements in small molecules with structural insights and SAR studies

Cancer represents one of the world's biggest hazardous diseases. p53 is the uttermost researched tumour suppressor protein. It is commonly considered the "guardian of the genome," performing a critical function in genetic stability maintenance through controlling the cell cycle, programmed cell death, DNA repair, aging, and angiogenesis. The abnormalities in p53 lead to genetic instability and plays a significant role in carcinogenesis. The role of p53 in tumour suppression is emphasized in addition by the observation that primary silencing with this protein occurred in more than 50% of cancers. MDM2, p53, and the p53-MDM2 connections are well-known targets for the prevention and treatment of cancer. Moreover, in tumors with wild-type p53, their efficacy is decreased due to MDM2 enlargement or by the gradual decrease of MDM2 blocker ARF. As a result, improving p53 activity in cancerous cells provides a promising anticancer strategy. Various techniques are now being investigated, and addressing the p53-MDM2 interaction had also evolved as a potentially feasible strategy for contending with tumors. Both p53 and MDM2, interact via an autoregulation response signal: p53 activity induces MDM2 transcription, which in response interacts with p53's N-terminal transactivation domain, inhibiting its transcriptional activity. This article provides information on the current scenario of anti-tumor activities, with a particular emphasis on structure-activity relationship characteristics (SAR) against the p53-MDM2 to treat cancer. The primary purpose of this review is to cover recent advancements in the creation and testing of anticancer drugs that target the p53-MDM2 structure. This review contains different heterocyclic moieties which show significant results toward cancer. A mechanistic route is shown here, demonstrating both normal and malignant conditions via several stressed factors. Several compounds entered clinical trials as p53-MDM2 inhibitors for the treatment of cancer.

Design, synthesis of 1,2,4-triazine derivatives as antidepressant and antioxidant agents: In vitro, in vivo and in silico studies

The novel series of substituted-N-(5,6-diphenyl-1,2,4-triazin-3-yl) benzamides (R: 1-12) were designed, synthesized and evaluated for in-vitro and in-vivo antidepressant-like activity. In MAO-A inhibition assay, compound R: 5 and R: 9 displayed most potent activity with IC₅₀ = 0.12 and 0.30 µM. R: 5 and R: 9 were also evaluated for in-vivo antidepressant using FST and TST. In both models, the test samples R: 5 and R: 9 showed noteworthy antidepressant effect. R: 5 showed 46.48 % and 45.96 % reduction in immobility in FST and TST respectively at dosage of 30 mg/kg (p.o). Whereas compound R: 9 reduced the immobility time by 52.76 % and 47.14 % as compared to control in FST and TST, respectively at same dosage. Both the compounds were also tested for behavioural study using actophotometer and grip tests. None of compounds exhibited decrease in locomotor activity. Further, these compounds were subjected to in silico studies to determine their ADME properties along with binding energies and binding orientions. In ADME studies none of the compounds violated the Lipinski rule and all other parameters were also within the acceptable ranges. In docking study R: 5 (-10.7) and R: 9 (-10.4) were also displayed highest docking score. These encouraging results present the pharmacophoric features of substituted-N-(5,6-diphenyl-1,2,4-triazin-3-yl) benzamides as interesting lead for further development of new antidepressant drug molecules.

Design, Synthesis, and Biological Evaluation of Novel Dihydropyrimidinone Derivatives as Potential Anticancer Agents and Tubulin Polymerization Inhibitors

The severity and prevalence of cancer in modern time are a huge global health burden. Continuous efforts are being made toward the development of newer therapeutic candidates to treat and manage this ailment. The dihydropyrimidinone scaffold is one of the key nuclei that have been highly explored and investigated against cancer. It has the potential to combat the consequences of cancer by interacting with several biological targets. Tubulin polymerization inhibition is one such strategy to prevent the progression of cancer. In the presented work, we have synthesized a series of sixteen dihydropyrimidinone derivatives by following a rational drug design. The synthesized compounds have been characterized by ¹H NMR and ¹³C NMR and were further evaluated for cytotoxic activity against breast cancer cell lines (MCF-7 and MDA-MB-231), lung cancer cell lines (A549), and colon cancer cell lines (HCT-116). Compounds 5D and 5P were found most potent and revealed a better cytotoxic activity compared with the standard drug colchicine. Furthermore, the tubulin polymerization inhibition assay revealed that compound 5D showed better inhibition than colchicines, whereas compound 5P revealed an almost equal inhibition to that of colchicine. Furthermore, to investigate the possible mode of action and binding patterns, compounds 5P and 5D were subjected to molecular docking against tubulin (Protein Data Bank ID: ISA0). The results showed that compounds revealed significant interactions and were well occupied inside the cavity of tubulin. The compounds 5D and 5P may serve as new leads in drug development against cancer.

Tivozanib: A New Hope for Treating Renal Cell Carcinoma

BACKGROUND

Renal cell carcinoma (RCC) is a diverse collection of malignancies with varying histological characteristics, molecular changes, prognosis, and therapeutic response. Tivozanib was first approved in March 2021 by USFDA with the brand name Fotivda. Tivozanib hydrochloride monohydrate is an oral medication that is used to treat relapsed or refractory renal cell carcinoma.

OBJECTIVE

In this review, we explain renal cell carcinoma and its different types of treatment by the anti-renal carcinoma drugs.

METHODS

A comprehensive literature search was conducted in the relevant databases, like ScienceDirect, PubMed, ResearchGate, and Google Scholar, to identify the studies.

CONCLUSION

Tivozanib is an oral VEGFR-1, VEGFR-2, and VEGFR-3 tyrosine kinase inhibitor that is extremely selective and powerful. It has much less affinity for other receptor tyrosine kinases than multi-targeted TKIs now in clinical use. Because of its long half-life in circulation, it may be able to block VEGFRs more consistently. Doserelated controllable hypertension is its most commonly seen drug-related side event. Fatigue, hoarseness, and diarrhea, which are all common side effects, are not dose-related. Because of its target specificity, tivozanib can work well with other medications that have low side effects. Blocking both the VEGF and mTOR signaling pathways at the same time provides the benefit of synergistic antitumor efficacy while also preventing treatment resistance. Thus, overall we can say that the drug tivozanib is suitable for treatment in patients with renal cell carcinoma and can be investigated in multi-center clinical trials.

US-FDA Approved Drugs in 2020 and 2021: A Review

Introduction:

Throughout the years, the disruption caused by COVID-19 continues to pose an excess of challenges for the pharmaceutical industry. Throughout the entire year, questions were raised that does COVID-19 have a negative impact on new drug approvals. However, the answer to those questions was a ‘big no’.

Methodology:

We propose a compilation and analysis of around 100 medications, including small new molecular entities (NMEs), approved by the US Food and Drug Administration for the years 2020 and 2021. Novel drug discovery is crucial for pharmaceutical research and development as well as patient care. The only possible way to achieve this crucial goal is to repurpose current medications that may have anticipated effects as possible candidates. The availability of new drugs and biological products often means new treatment options for patients and advances in health care

Results:

Around 40% of the drugs were approved for various types of cancers. Other major therapeutic areas that were focused on were neurological products (around 17%), infectious diseases (13-15%), and cardiovascular disorders (7-8%). Various new products were approved for rare diseases (58-60%). This study aimed to discover a pattern in FDA medicine approvals during the last two decades.

Conclusion:

This data shows that anticancer medicines and biologics are receiving increased attention in research. With a bigger number of biologically derived medications being produced, the price could rise much higher. FDA should embrace innovative techniques that will stimulate the industry to enhance research and development of novel compounds or medications that can deliver considerable improvements over existing ones. To put it briefly, FDA had to update our approach to regulation as a whole in order to effectively develop the types of technologies that are becoming available. Modernizing medical product review programmes is a part of this. These initiatives are part of the Medical Innovation Access Plan.

An update on recently developed analytical and bio-analytical methods for some anticancer drugs

Abstracts:

According to the WHO’s data for 2018, the global cancer burden was estimated to have risen to 18.1 million new cases and which alone accounted for 9.6 million deaths. Cancer is a group of diseases known as tumors that often spreads throughout the body, and may cause harm to multiple organs in the body. The global pharmaceutical spending is around 19% of the R&D cost annually to discover new and potent therapeutic agents. The major problems associated with currently available anticancer drugs are drug resistance and their side effects. They are the most widely explored groups of drugs either using instrumental or bioanalytical methods. In this review, we have compiled and reviewed the analytical and bio-analytical methods of some anticancer drugs developed by different authors. The review also briefly discusses the broad categories of cytotoxic drugs and targeted-based anticancer drugs. The analytical and bioanalytical methods of cytotoxic drugs such as alkylating agents, antimetabolites, hormones, and targeted-based drugs reported earlier and in recent research, articles are discussed in detail. These analytical methods are prerequisites for both the pharmaceutical industry and academics for their impurities profiling and qualitative as well as quantitative estimation. The accuracy, precision, LOD, and LOQ studies by UV-HPLC, LC-MS, and fluorometry HPLC are discussed. Some of the advanced methods developed, in the case of ifosfamide using Au/Pd@rGO@p(L-Cys) and the production of vincristine by endophytic fungi, are also included. This will further embolden the efforts of different researchers working in this field and ease the challenges they face through the analytical development of these drugs.

How should we secure the cystic duct during laparoscopic cholecystectomy? A UK-wide survey of clinical practice and systematic review of the literature with meta-analysis

INTRODUCTION

It is currently unknown which method of cystic duct closure is most effective at reducing the risk of bile leak after laparoscopic cholecystectomy. The aims of this work were to determine the most common closure methods used in the UK and review available evidence on which method has the lowest risk of bile leak.

METHODS

We conducted an online survey through the Association of Upper Gastrointestinal Surgeons (AUGIS). We also undertook a systematic review using PubMed, EMBASE, MEDLINE and the Cochrane Library for studies that compared different methods for cystic duct occlusion and reported postoperative bile leak.

FINDINGS

There was significant variation in practice between consultant surgeons. For routine laparoscopic cholecystectomy metal clips were used most (64%) followed by locking polymer clips (33%) and suture ties (3%). In cases of a dilated cystic duct, preferences were locking polymer clips (60%), suture ties (30%) and metal clips (5%). We included six studies in our review with a total of 8,011 patients. Metal clips were associated with an increased odds of bile leak compared with locking polymer clips (OR 5.66, 95% CI 1.13-28.41, p=0.04) or suture ties (OR 4.17, 95% CI 0.72-24.31, p=0.12). Most studies were retrospective, unlikely to be adequately powered, and vulnerable to selection bias.

CONCLUSIONS

Limited available evidence suggests that metal clips have the highest risk of bile leak, but results are not strong enough to recommend a change in current clinical practice. A trial is now required to determine the best method of cystic duct closure.

Imaging Breast Microcalcifications Using Dark-Field Signal in Propagation-Based Phase-Contrast Tomography

Breast microcalcifications are an important primary radiological indicator of breast cancer. However, microcalcification classification and diagnosis may be still challenging for radiologists due to limitations of the standard 2D mammography technique, including spatial and contrast resolution. In this study, we propose an approach to improve the detection of microcalcifications in propagation-based phase-contrast X-ray computed tomography of breast tissues. Five fresh mastectomies containing microcalcifications were scanned at different X-ray energies and radiation doses using synchrotron radiation. Both bright-field (i.e. conventional phase-retrieved images) and dark-field images were extracted from the same data sets using different image processing methods. A quantitative analysis was performed in terms of visibility and contrast-to-noise ratio of microcalcifications. The results show that while the signal-to-noise and the contrast-to-noise ratios are lower, the visibility of the microcalcifications is more than two times higher in the dark-field images compared to the bright-field images. Dark-field images have also provided more accurate information about the size and shape of the microcalcifications.

Various Analytical Methods for Estimation of Potassium Sorbate in Food Products: A Review

Abstract:

Food preservatives are used to keep bacteria, moulds, fungus, and yeast from spoiling food. Food additives are subject to strict rules (particularly in the European Union - EU), which consider the food to which they can be applied, maximum permissible quantities, chemical characterization, and purity. Sorbic acid, mainly potassium sorbate, is primarily utilised in a variety of commercially available foods. Various analytical strategies for an asynchronous and simultaneous estimation of potassium sorbate have been reported along with other preservatives in marketed formulations or food products. The Square-wave voltammetry using a cathodically prepared boron-doped diamond electrode, quick UHPLC–fluorescent method, UV spectrophotometry, UHPLC-UV analysis, RP-HPLC, and mass spectrometry are some of the analytical techniques used. We have compiled various analytical methods to detect potassium sorbate with various other preservatives simultaneously or alone in marketed formulation. The authors feel that the studies summarised in this report will allow readers to choose the most acceptable and appropriate method for analysing this preservative.

Design Strategies, Chemistry and Therapeutic Insights of Multi-target Directed Ligands as Antidepressant Agents

Depression is one of the major disorders of the central nervous system worldwide and causes disability and functional impairment. According to the World Health Organization, around 265 million people worldwide are affected by depression. Currently marketed antidepressant drugs take weeks or even months to show anticipated clinical efficacy but remain ineffective in treating suicidal thoughts and cognitive impairment. Due to the multifactorial complexity of the disease, single-target drugs do not always produce satisfactory results and lack the desired level of therapeutic efficacy. Recent literature reports have revealed improved therapeutic potential of multi-target directed ligands due to their synergistic potency and better safety. Medicinal chemists have gone to great extents to design multitarget ligands by generating structural hybrids of different key pharmacophores with improved binding affinities and potency towards different receptors or enzymes. This article has compiled the design strategies of recently published multi-target directed ligands as antidepressant agents. Their biological evaluation, structural-activity relationships, mechanistic and in silico studies have also been described. This article will prove to be highly useful for the researchers to design and develop multi-target ligands as antidepressants with high potency and therapeutic efficacy.

Design, Synthesis, and Pharmacological Evaluation of N-Propargylated Diphenylpyrimidines as Multitarget Directed Ligands for the Treatment of Alzheimer's Disease

Alzheimer's disease (AD), a multifactorial complex neural disorder, is categorized with progressive memory loss and cognitive impairment as main clinical features. The multitarget directed ligand (MTDL) strategy is explored for the treatment of multifactorial diseases such as cancer and AD. Herein, we report the synthesis and screening of 24 N-propargyl-substituted diphenylpyrimidine derivatives as MTDLs against acetylcholine/butyrylcholine esterases and monoamine oxidase enzymes. In this series, VP1 showed the most potent MAO-B inhibitory activity with an IC₅₀ value of 0.04 ± 0.002 μM. VP15 with an IC₅₀ value of 0.04 ± 0.003 μM and a selectivity index of 626 (over BuChE) displayed the most potent AChE inhibitory activity in this series. In the reactive oxygen species (ROS) inhibition studies, VP1 reduced intercellular ROS levels in SH-SY5Y cells by 36%. This series of compounds also exhibited potent neuroprotective potential against 6-hydroxydopamine-induced neuronal damage in SH-SY5Y cells with up to 90% recovery. In the in vivo studies in the rats, the hydrochloride salt of VP15 was orally administered and found to cross the blood-brain barrier and reach the target site. VP15·HCl significantly attenuated the spatial memory impairment and improved the cognitive deficits in the mice. This series of compounds were found to be irreversible inhibitors and showed no cytotoxicity against neuronal cells. In in silico studies, the compounds attained thermodynamically stable orientation with complete occupancy at the active site of the receptors. Thus, N-propargyl-substituted diphenylpyrimidines displayed drug-like characteristics and have the potential to be developed as MTDLs for the effective treatment of AD.

The growing concern of chlorpyrifos exposures on human and environmental health

Chlorpyrifos (CP) and its highly electrophilic intermediates are principal toxic metabolites. The active form of CP i.e. chlorpyrifos oxon (CP-oxon) is responsible for both the insecticidal activity and is also of greater risk when present in the atmosphere. Thus, the combined effects of both CP, CP-oxan, and other metabolites enhance our understanding of the safety and risk of the insecticide CP. They cause major toxicities such as AChE inhibition, oxidative stress, and endocrine disruption. Further, it can have adverse hematological, musculoskeletal, renal, ocular, and dermal effects. Excessive use of this compound results in poisoning and potentially kills a non-target species upon exposure including humans. Several examples of reactive metabolites toxicities on plants, aquatic life, and soil are presented herein. The review covers the general overview on reactive metabolites of CP, chemistry and their mechanism through toxic effects on humans as well as on the environment. Considerable progress has been made in the replacement or alternative to CP. The different strategies including antidote mechanisms for the prevention and treatment of CP poisoning are discussed in this review. The approach analyses also the active metabolites for the pesticide activity and thus it becomes more important to know the pesticide and toxicity dose of CP as much as possible.