816 research outputs found
Isolation and Physiomorphological Characterization of Escherichia coli
Bacteriophages, recovered from beef cattle environment and specifically targeting Escherichia coli O157:H7, were examined for their physiological and morphological characteristics. Degree of bacterial lysis and host range of isolated bacteriophages was determined against 55 isolates of E. coli O157:H7. Morphology of phages was examined under transmission electron microscope. Phage growth parameters, particularly rate of adsorption, rise period, latent period, and burst size were also determined. The stability of isolated phages was tested at acidic and alkaline pH, at high temperatures, and in cold storage. A total of 7 phages were isolated which showed lytic activity against 50 out of 55 isolates of E. coli O157:H7. Based on the morphology, phages were classified into Myoviridae or Siphoviridae family. Phages had a rise period between 19 and 40 min, a short latent period between 12 and 30 min, and a large burst size (89–631 virions per infected cell), indicating high lytic activity. Phages remained stable for 24 h at a wide pH (1–11) and temperature range (40–60°C) and for 90 d in cold storage. Characterization of bacteriophages, with a diverse host range of E. coli O157:H7, could aid in the development of effective biocontrol strategies for this pathogen in the food industry
Analyzing the Effect of Scintillation on Free Space Optics
Owing to the unique features of free space optics such as high data rate, large bandwidth, easy installation and license free spectrum, this wireless technology is gaining a lot of momentum nowadays. Since the medium through which the signal travels is atmosphere, the performance of the system primarily depends upon the weather. Scintillation is one of the major concerns which is caused by variation in refractive index of air due to change in temperature. In this paper, the effect of scintillation on the performance of FSO system is analyzed in terms of eye diagrams, BER and Q-factor
Urinary tract infection in women of rural population of Haryana: a rising problem
Background: The study was aimed to understand the clinico-pathological characteristics of urinary tract infection along with the techniques used in diagnosis and treatment of the presenting infection. The study takes into consideration the various risk factors such as age, marital, socioeconomic status which influences the risk of having UTI.Methods: The study was conducted in Adesh Medical College, Mohri district. A questionnaire was prepared in accordance to evaluate risk factors of urinary tract infection. The patients under study were chosen according to specific inclusion criteria. The patients presenting with symptoms of UTI were subjected to examination and then urine culture and sensitivity test. The uropathogens were isolated with the help of biochemical testing.Results: Out of 500 women who atteneded gynae opd of Adesh Medical College, Mohri district were taken into study out of 500 patients 296 patients showed positive culture. UTI was found more in married females which were illiterate and belonged to low socioeconomic group. E.coli was the most common organism which was cultured. E.coli (55%) was found to be the most prevalent organism followed by Klebsiella.Conclusions: UTIs are some of the most common bacterial infections in women. Women with UTI need to be properly investigated by urinalysis and urine culture. Marital status, socioeconomic status has high impact on the lifetime risk for UTI. E.coli was found to be the most common cause of UTI in all the age groups
Dual Role of the Metalloprotease FtsH in Biogenesis of the DrrAB Drug Transporter
This study provides the first direct evidence for the dual role of the metalloprotease FtsH in membrane protein biogenesis. Using the physiological substrate DrrAB, it is shown that FtsH is not only responsible for proteolysis of unassembled DrrB protein but it also plays a much broader role in biogenesis of the DrrAB complex. Previous studies showed that the stable expression of DrrB in the membrane depends on simultaneous expression of DrrA. Here we show that DrrB is proteolyzed by FtsH when it is expressed alone. Moreover, DrrA and DrrB proteins expressed together in a temp-sensitive ftsH mutant strain of E. coli were found to be non-functional due to their incorrect assembly. Simultaneous expression of wild-type FtsH in trans resulted in normal doxorubicin efflux. Strikingly, doxorubicin efflux could be restored in mutant cells irrespective of whether FtsH was expressed simultaneously with DrrAB or expressed after these proteins had already accumulated in an inactive conformation, thus providing crucial evidence for the ability of FtsH to refold the misassembled proteins. Complementation experiments also showed that the catalytic AAA domain of FtsH contains a chaperone-like activity, however, unlike wild-type FtsH, it was unable to restore function. Our results therefore show for the first time that FtsH contains the protease as well as refolding functions, and both the AAA and the proteolytic domains of FtsH are required for each of these activities
A rare case of nulliparous prolapse at term
Uterovaginal prolapse complicating pregnancy is an extremely rare event. Obstetricians should be familiar with the condition as early recognition and close follow up is essential in order to avoid possible fetomaternal risks. Its incidence is higher in women of advanced age and parity. This case report presents a rare occurrence of prolapse in nulliparous woman. In the present case report, we describe a case of a 24 year-old nulliparous female who experienced sudden uterine prolapse at 38 weeks of gestation without labor. She was delivered by cesarean section in view of primi with breech. Following delivery, the prolapse promptly improved and did not recur
Thianthrene is a novel inhibitor of Leishmania donovani pteridine reductase 1 (PTR1)
Pteridine reductase 1 (PTR1) from Leishmania donovani is a short chain reductase that catalyses the NADPH-dependent reduction of folates and pterins. It has gained attention as a therapeutic target because it acts as a metabolic bypass for dihydrofolate reductase (DHFR) targeting drugs and is thought to be responsible for the failure of conventional therapies against the trypanosomatids. In the present study, we report the identification of thianthrene as a potent inhibitor of L. donovani PTR1 (LdPTR1) based on both structure-based virtual screening and experimental verification. Thianthrene displayed uncompetitive mixed type inhibition in a recombinant enzyme inhibition assay. In addition, cell based assays and flow cytometry showed that the intracellular amastigotes were inhibited by thianthrene in vitro. The results of our study could be considered for the development of novel therapeutics based on PTR1 inhibition
Smart Walking System based on Artificial Intelligence
This paper shows the smart walking stick based on ultrasonic sensors and Arduino for outwardly debilitated individuals. There are roughly 37 million individuals over the globe who are visually impaired as indicated by the World Health Organization. Individuals with visual inabilities are regularly subjected to outer help which can be given by people, trained dogs, or electronic gadgets as supportive networks for basic assistance. Thus, this played as the motivation to develop a smart cane white stick to survive these restrictions which includes ultrasonic sensors at particular positions to the stick that gave data about nature to the client by initiating the signal sound and vibrations. We proposed minimal effort and light weight framework structured with micro controller that processes signal and alerts the visually impaired person over any obstacle, water or dark areas through beeping sounds or vibrations. The system comprises of obstacle and moisture detection sensors for process of receiving, processing and sending signals to the alarm system which finally alerts the user for prompt action. The system was designed, programmed using Java language and tried for exactness by the visually impaired. Our gadget can recognize obstacle inside the separation of around 2m from the client
Clinical evaluation of adding solitary dose of magnesium to fentanyl on post-operative analgesia during combined spinal epidural technique for hip replacement procedures
Background: Numerous receptors such as NMDA have evolved in the management of post-operative pain which can be antagonized effectively before the initiation of painful stimuli. The analgesic property of Magnesium is primarily related to the regulation of calcium influx and antagonism of N-methyl-D-aspartate (NMDA) receptors distributed throughout the central nervous system. This study was designed to evaluate if addition of magnesium to epidural fentanyl as pre-emptive solitary dose could prolong post-operative analgesia during combined spinal epidural anesthesia in elective hip replacement surgeries.Methods: A total of 63 adult consented ASA grade I and II patients aged between 40 and 70 years of either sex, who met the inclusion criteria for hip replacement surgery, were randomized to receive either epidural fentanyl (Group I) or combined epidural magnesium sulphate and fentanyl (Group II). Both the groups subsequently received subarachnoid block with 0.5 % heavy bupivacaine. Intraoperative hemodynamic, subarachnoid block characteristics and 24 hours post-operative analgesia was evaluated.Results: There was significant delay in two dermatome regression for the combined fentanyl magnesium group (149.07±6.48 min) compared to fentanyl alone group (121.23±2.92 min). The post-operative VAS score was statistically lower for the combined fentanyl magnesium group (lowest:0.7±0.4 at 4th hr, highest: 2.9±0.3 at 20th hr) compared to fentanyl alone group (lowest:1.86±1.7 at 5th hr, highest: 3.37±0.9 at 4th hr). There was highly significant difference in average time to first epidural top up and 24hrs epidural top up consumption between fentanyl alone group (264.83±34.08min, 2.8±0.5) and combined fentanyl magnesium group (398±69.55min, 1.43±0.5). Total epidural top ups were 84 in fentanyl alone group and 43 in combined fentanyl magnesium group. Hemodynamic parameters were stable in both groups.Conclusions: Pre-emptive co-administration of magnesium sulphate as a solitary dose to epidural fentanyl in CSE technique prolongs the duration of post-operative analgesia, reduce the requirement of epidural top up and provide stable hemodynamic perioperatively compared to epidural fentanyl alone.
Toward understanding the S2-S3 transition in the Kok cycle of Photosystem II:Lessons from Sr-substituted structure
Understanding the water oxidation mechanism in Photosystem II (PSII) stimulates the design of biomimetic artificial systems that can convert solar energy into hydrogen fuel efficiently. The Sr2+-substituted PSII is active but slower than with the native Ca2+ containing PSII as an oxygen evolving catalyst. Here, we use Density Functional Theory (DFT) to compare the energetics of the S2 to S3 transition in the Mn4O5Ca2+ and Mn4O5Sr2+ clusters. The calculations show that deprotonation of the water bound to Ca2+ (W3), required for the S2 to S3 transition, is energetically more favorable in Mn4O5Ca2+ than Mn4O5Sr2+. In addition, we have calculated the pKa of the water that bridges Mn4 and the Ca2+/Sr2+ in the S2 state using continuum electrostatics. The calculations show that the pKa is higher by 4 pH units in the Mn4O5Sr2+cluster
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