Pharmacological investigation of Thespesea populnea bark extract for analgesic activity

Background: Pain is an unpleasant and distressing common problem with profound impact on individuals and society. Existing treatment modalities used for pain management are either less effective or exhibits several side effects. The aim of current study is to investigate the analgesic activity of stem bark extract of Thespesea populnea for pain management.Methods: Thirty Swiss albino were divided into five groups including control, standard and three tests groups (different doses of Thespesea populnea bark extract). Groups were investigated for analgesic activity using hot plate induced paw withdrawal, acetic acid induced writhing and formalin induced paw licking models.Results: Findings of hot plate model revealed that, percent increase in reflex latency of paw licking response in mice for test drug (10 mg/kg), attained peak effect of 136% at 180 minutes, whereas for standard pentazocine peak effect of 125% was attained at 180 minutes. In acetic acid model, the maximum percent inhibition in number of writhings for the test drug (30 mg/kg) was 68% and for standard diclofenac, it was 80%. In formalin model, percent inhibition in licking response in early and late phases for test drug (30 mg/kg) were 81% and 91% and for standard diclofenac it was 56% and 94% respectively. It was thus depicted that analgesic activity of test drug was significantly more than the standard in early phase and equivalent to standard in late phase.Conclusions: It was concluded that Thespesea populnea bark extract at a dose of 10 mg/kg showed potential peripheral and central analgesic activity

Phosphorous containing chitosan beads for controlled oral drug delivery

Phosphorous containing chitosan (PCTS) was synthesized by a graft copolymerization technique in order to be used as controlled drug delivery devices. To test this potential, PCTS beads were prepared by using tripolyphosphate, at pH 4.0 and characterized by scanning electron microscopy. The in vitro drug release behavior in various pH solutions was studied using indomethacin (IM) as a model drug at two different concentrations (0.3 and 0.6% w/w). The release percent of IM from PCTS beads was found to be increased with the increasing of pH in the buffer solution. The release rate of IM at pH 7.4 was higher than that at pH 1.4, due to the ionization of phosphorous groups and the high solubility of IM in the alkaline medium. These results indicated that PCTS beads have the potential to be used as controlled drug delivery systems through oral administration by avoiding the drug release in the highly acidic gastric fluid region of the stomach

Durability Map for The Friction Stir Welding Tools with Flat Faced Pins

In friction stir welding, tools made with flat faced pins deliver comparatively higher strength joints than circular pins. However, its non-axisymmetric cross section about the rotational axis results in fluctuating stress along its surface that leads to premature tool failure. This requires a systematic definition for process parameter selection domain based on the number of flat faces in the pin to improve tool life. Temperature dependent strength of the material to be joined in the stir zone is the only source of opposing force for the tool movement. To predict opposing force, temperature gradient developed by the different levels of process parameters in the stir zone is numerically quantified with an experimentally validated model. Based on the estimated temperature, maximum stress acting on the tool pin is quantified with a remodified temperature dependent analytical model. The effect of increase in process temperature on the strength of the weld joint is experimentally analysed through the investigation of change in hardness value in heat affected zone. Obtained results are used to develop tool durability maps for tools with flat faced pin in a domain on which higher and lower limits are fixed by considering satisfactory level of joint strength and tool life respectively. These maps provide flexibility in the parameter selection with an acceptable level of compromise in joint strength or in tool life based on the quality requirement of weld joint

Data-driven Network Connectivity Analysis: An Underestimated Metric

In the network structure analysis, we explore an underestimated key metric, the Relative Size of Largest Connected Component (RSLCC) and demonstrate its importance in post-disaster network connectivity assessment. RSLCC was first investigated in the study of complex network structures, but remains largely unexplored in terms of analysis within a specific application domain such as scenarios in transportation networks, wireless networks, communication networks, power networks, etc. Through the research presented in this paper, we not only prove that this metric is underestimated, but also design 7 methods to predict the value of this metric, with a Deep Neural Network (DNN) prediction accuracy of more than 99%. This study focuses on the assessment and analysis of post-disaster network connectivity, by exploring how the RSLCC, a key metric of network connectivity, can be used to efficiently predict and assess network connectivity in a disaster scenario, specifically, the approximate network connectivity value can be predicted simply by knowing the number of connected edges in the pre-disaster network and the number of connected edges in the post-disaster network. To achieve this, firstly, a sufficiently large-scale 100,000 datasets containing the values of attributes related to the network structure is prepared. Secondly, based on the preprocessing of the data, principal component analysis and variance contribution analysis are carried out, and the metric with the highest contribution to the principal component is approximated as the network connectivity. The next step is the prediction process, Network Disruption Degree (NDD) is chosen as the independent variable. since it is best to choose an extremely simple metric as the independent variable for prediction, rather than all network structure-related metrics, this paper demonstrates that it is possible to get satisfactory prediction results with this metric. It is found that NDD prediction methods have the highest prediction accuracy but take the longest run time and require training data of a sufficiently large size. If the prediction is done in small-size data, then Random Forest Regression (RFR) is proven to have the highest prediction accuracy. Although the network connectivity metric proposed in this paper is only an approximation, it provides good directions for simplifying the network connectivity analysis and the use of this metric for the study of practical modeling problems is also highly interpretable

Relief network design problem (RNDP): A scoping review, challenges, and opportunities

The Relief Network Design Problem (RNDP) is particularly important in emergency management. Any uncertain factors caused by natural disasters, the equity measurement in network design, and the adequate analysis of relief behavior will affect the efficiency of the relief network. This paper provides a comprehensive basis to support this view. The scope of the review allowed for exploring all existing literature on RNDP, where screening for titles, abstracts, keywords, and main contents, a total of 629 relevant articles are preserved. To construct the review work, existing research perspectives on the Relief Logistics Network Design Problem (RLNDP) as well as the Relief Transport Network Design Problem (RTNDP) are addressed, and their research focus and main research approaches are discussed. The existing studies on RNDP seem to be reached a bottleneck on how to design a humanitarian relief network. Hence, this paper contributes to the existing body of knowledge by summarizing the literature in the field, identifying gaps, analyzing future challenges, and providing solutions for future research. Specifically, this review reveals that while a large number of studies have considered uncertainty in the network design, they have not considered it at both the management level and the residents' level. In addition, equity is often mentioned, but the definition of humanitarian equity is unclear, as most studies consider equity at the management level. In real disaster relief scenarios, people do not only wait for relief, but self-evacuation is also a main behavior in the relief process, yet there are few studies that consider it in the network design. This review also emphasizes the relief network design structure problem, and the interdependence and coupling of the relief infrastructure transport or logistics facility network with other networks, such as the electric network, energy network, etc., deserves to be focused. In summary, five valuable research highlights are proposed based on a review of the existing literature: (1) Explore uncertainties from both the government management and disaster victim perspectives and integrate them into network design approaches. (2) Define and consider relief equity from both the government management and disaster victim perspectives. (3) Analyze self-evacuation behavior in the emergency relief phase and explore how it affects RNDP. (4) Optimize the transfer point location and relief routing from the perspective of management and humanitarian equity. (5) Strengthen the resilience of disaster relief interdependent network

Screening of a novel-substituted furan compound for analgesic activity in mice

Background: Pain is an unpleasant sensation and is the most primitive of all senses. It is a major symptom in many medical conditions and can significantly interfere with a person's quality of life and general functioning. Analgesics like opioids and NSAIDS are used to treat pain but due to their side effects on long term use it is necessary to develop a compound with reduced side effects. Hence the present study was focused on screening of novel compound of novel compound 2-(4-nitrophenylimino)-N-cyclohexyl-4,5 diphenylfuran-3- carboxamide (AMSM-2(a-k) for analgesic activity in mice.Methods: The analgesic activity of test compound AMSM-2(a-k) at different doses (5 mg/kg, 10 mg/kg and 20 mg/kg) was evaluated by using Eddy’s hot plate for determining central analgesic activity using morphine (5 mg/kg) as standard drug, acetic acid induced writhing test for peripheral analgesic activity and formalin induced writhing test to evaluate both central and peripheral analgesic activity using aspirin as standard drug (300 mg/kg). The percentages of inhibition of writhing’s were calculated for acetic acid and formalin induced pain model. The statistical analysis was done using one way ANOVA followed by Dunnett’s test. All values with P <0.05 were considered statistically significant.Results: In hot plate method, the percentage increase in the latency of licking for test compound AMSM-2(a-k) at 20 mg/kg was significantly comparable to standard drug. Morphine (10 mg/kg) and AMSM-2(a-k) (20 mg/kg) gave the peak effect at 90 minutes. In acetic acid induced writhing method the percentage inhibition for AMSM-2(a-k) (20 mg/kg) was 73.93% for up to 20 min and for aspirin was 57.12%. In formalin induced paw licking method, the percentage inhibition in licking response in the early phase for AMSM-2(a-k) with 20 mg/kg was 63.23% which was more significant than the standard drug aspirin (100 mg/kg) which gave a percentage inhibition of 42.17%. In the late phase the percentage inhibition in licking response for AMSM-2(a-k) (20 mg/kg) was 74.33% and aspirin (100 mg/kg) gave a percentage inhibition of 60.82%.Conclusions: The test drug AMSM-2(a-k) at a dose of 20 mg/kg showed promising results in hot plate method, equally comparable to the standard drug morphine and in acetic acid induced writhing test and formalin induced paw licking (early and late phase) methods they are more significant than the standard drug aspirin. This suggests AMSM-2(a-k) had potential central and peripheral analgesic activity

Failure Analysis of A 304 SS Girdling Loop of the Boiler in a 500 MW Thermal Power Plant

There were many cases of girdling loop failures in the reheater section of the 500 MW boilers of athermal power station after being in service relatively for a short period of a few months. Within seven months of synchron-ization, the bottom 'U'portion of the front reheater girdling loop of the boiler of 500 MW thermal power plant had developed a leak. The plant was restarted alter replacing the failed protion of the type 304 stain-less steel 'U' tube. Failure occurred again within seven months of operation. Similar failures followed in the other units of the station

Effect of oral clonidine premedication on attenuating haemodynamic response to laryngoscopy and intubation during general anaesthesia

Background: Laryngoscopy with or without tracheal intubation evokes a defense mechanism that in turn alters patients’ haemodynamic responses in terms of increased heart rate (HR) and arterial blood pressure (ABP). Aim of current investigation was to study the efficacy of orally administered clonidine in a dose of 3-3.5 µg/kg given 90 minutes prior to scheduled time of the surgery, in attenuating the adverse haemodynamic responses to laryngoscopy and intubation of the trachea. Methods: Eighty normotensive patients between 20-60 years of age and having ASA grade I/II physical status were subdivided in two groups with 40 patients in each; test group received clonidine in a dose of 3-3.5 mcg/kg of body weight orally, 90 min before surgery and control group did not receive clonidine premedication. Induction was done with Thiopentone intravenous injection (5 mg/kg), followed by succinylcholine (1-1.5 mg/kg). Results: Haemodynamic responses in terms of parameters like HR, systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP) were recorded at pre induction and at 1, 2, 3, 5 minutes following laryngoscopy. The 1-minute post induction values of SBP, DBP, MAP were significantly less in clonidine group (p&lt;0.001) and the significance in listed parameters between two groups persisted until 5 minutes. Increase in HR was less in clonidine group than in control group. Conclusions: Premedication with oral clonidine 3-3.5 mcg/kg of body weight, 90 minutes before laryngoscopy and intubation is an efficient, simple and inexpensive method in attenuating the haemodynamic response generated due to laryngoscopy and intubation

Chemistry and applications of phosphorylated chitin and chitosan

Chitin and chitosan are natural based non-toxic, biodegradable and biocompatible polymers and have been used in biomedical areas in the form of sutures, wound healing materials and artificial skin, and for the sustained release of drugs as well as in various industrial applications. However, practical use of these polymers has been mainly confined to the unmodified forms. Recently, there has been a growing interest in chemical modification of chitin and chitosan to improve their solubility and widen their applications. Among them, phosphorylated chitin and chitosan have attracted considerable interest because of their various advantages: anti-inflammatory property, ability to form metal complexes, blood compatibility and formation of anionic polyelectrolyte hydrogels. The purpose of this review is to take a closer look of different synthetic methods of phosphorylated chitin and chitosan and their potential applications in environmental, food, fuel cell, and biomedical fields. Based on current research and existing products, some new and futuristic approaches in this context area are discussed.R. Jayakumar acknowledges the Portuguese Foundation for Science and Technology for providing him a Post-Doc scholarship (SFRH/BPD/14670/2003). This work was partially supported by FCT Foundation for Science and Technology, through funds from the POCTI and/or FEDER program. This work was partially supported by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758)