A Fault Tolerant 3-Phase Adjustable Speed Drive Topology with Common Mode Voltage Suppression

A fault tolerant adjustable speed drive (ASD) topology is introduced in this work. A conventional ASD topology is modified to address: a) drive vulnerability to semiconductor device faults b) input voltage sags c) motor vulnerability to effects of long leads and d) achieve active minimization of common mode (CM) voltage applied to the motor terminals. These objectives are attained by inclusion of an auxiliary IGBT inverter leg, three auxiliary diodes, and isolation - reconfiguration circuit. The design and operation of the proposed topology modifications are described for different modes; (A) Fault mode, (B) Auxiliary Sag Compensation (ASC) mode and (C) Active Common Mode Suppression mode. In case of fault and sag, the isolation and hardware reconfiguration are performed in a controlled manner using triacs/anti-parallel thyristors/solid state relays. In normal operation, the auxiliary leg is controlled to actively suppress common mode voltage. For inverter IGBT failures (short circuit and open circuit), the auxiliary leg is used as a redundant leg. During voltage sags, the auxiliary leg along with auxiliary diodes is operated as a boost converter. A current shaping control strategy is proposed for the ASC mode. A detailed analysis of common mode performance of the proposed topology is provided and a new figure of merit, Common Mode Distortion Ratio (CMDR) is introduced to compare the attenuation of common mode voltage with that of a conventional ASD topology for three different modulation strategies. The output filter design procedure is outlined. A design example is presented for an 80 kW ASD system and simulation results validate the proposed auxiliary leg based fault tolerant scheme. Experimental results from a scaled prototype rated at 1 hp prototype also confirm the operation. The common mode analysis is also validated with the experimental results

Magnetic resonance imaging brain findings of pediatric HIV cases and its correlation with clinical and immunological stages of the disease: A study from a tertiary care center of Rajasthan

Objective: To study the magnetic resonance imaging (MRI) brain findings in pediatric HIV patients and to correlate them with clinical and immunological staging. Methods: This study was conducted in the Department of Pediatrics of a Teaching Institute of Rajasthan. It was a prospective longitudinal study, conducted over a period of 15 months (April 2008-July 2009). Diagnosis of HIV was confirmed and classified in clinical stages and immunologic stages as per NACO guidelines. MRI brain was done in every patient. Patients with abnormal MRI brain findings were further studied and correlated with clinical findings and CD4+ cell counts. Results: We had total 109 HIV-positive patients registered with us; out of these, 90 were in regular follow-up. Out of these 90 patients, 16 subjects (17.78%) showed abnormal neuroimaging features on MRI brain. No case presented with abnormal MRI features in clinical Stage I and II. 4 were in clinical Stage III, and 12 were in Stage IV. No case presented with abnormal MRI in immunological Stage I and II. 5 cases (31.25%) were in immunological Stage III and 11 (68.75%) in Stage IV. Out of total 90 subjects, only 10 patients had abnormal clinical (neurological) manifestations and rested 80 patients were neurologically and developmentally normal. 6 out of 16 (37.5%) patients with abnormal MRI brain findings did not show any neurological manifestations. The most common MRI brain abnormality noted was cerebral atrophy in 7 (43.75%) cases followed by nonspecific demyelination in 31.25% cases, and ventriculomegaly, nonspecific calcification, and infarcts in 3 (18.75%) subjects each and cerebellar atrophy in 2 subjects. Conclusions: Our study demonstrated that abnormalities of MRI brain increases with increasing immunosuppression and advancing clinical stage. We did not found any significant correlation with age and sex with abnormal MRI brain findings. Importantly, HIV‑positive children may present with only abnormal MRI brain findings without any clinical manifestation

Laparoscopic management of giant ovarian cyst in young woman: a case report

Giant ovarian cysts are very rare nowadays and were conventionally treated by full midline laparotomy. In recent years, the laparoscopic approach is also practiced but it needs a lot of expertise and only a few cases have been reported. As the surgical treatment of choice has become less invasive, laparoscopic surgery is considered more beneficial over laparotomy because of better cosmetic results, less blood loss, reduced postoperative analgesic requirement, early mobilization and faster discharge from the hospital and early resumption to normal day to day activity. We report a case of laparoscopic extirpation of a giant right ovarian cyst measuring 15 × 21 × 22 cm in young 24-year female

Spinal cord atrophy and myelomalacia following triple intrathecal chemotherapy in a patient of relapsed acute lymphoblastic leukemia

Paraplegia in a case of leukemia is an uncommon finding. It can be disease related, therapy related, or both. It may or maynot be reversible or curable. Here, we are discussing an unusual acute life-threatening, therapy related condition, where tripleintrathecal therapy in a relapsed acute lymphoblastic leukemia child led to severe spinal cord atrophy and myelomalacia causingacute paraplegia with urinary retention. Subsequently, the patient developed respiratory failure and succumbed to death. There isvery few case reported of this complication. The aim of this case report is to sensitize, the pediatricians and pediatric oncologistsabout this life-threatening complication of chemotherapy

SYNTHESIS, COMPUTER AIDED SCREENING AND PHARMACOLOGICAL EVALUATION OF 2/3-SUBSTITUTED-6(4-METHYLPHENYL)-4,5-DIHYDROPYRIDAZIN3(2H)-ONES, AND PYRIDAZINE SUBSTITUTED TRIAZINE

The present research work involved synthesis of some novel pyridazine derivatives and evaluation of their analgesic and anti-inflammatory activities in experimental animals to obtain safer non-steroidal anti-inflammatory drugs (NSAIDs). Friedal craft acylation reaction of succinic anhydride with toluene in the presence of anhydrous aluminum chloride gave 4-(4-methylphenyl)-4-oxo-butanoic acid (1). The aryl propionic acid 1 on reaction with phenyl hydrazine and hydrazine hydrate yielded the pyridazinone derivative 2 and 3, respectively. Reaction of the compound 3 with phosphorus oxychloride (POCl3) produced the corresponding chloropyridazine derivative 4. A 4-hydroxymethyl derivative of dihydropyridazinone (5) was synthesized by condensing 3 with methanol and formaldehyde (HCHO). The compound 5 on further treatment with guanidine hydrochloride in ethanol gave the pyridazino-triazine (6). The synthesized compounds were investigated for their analgesic activity in mice and anti-inflammatory activity in Wistar albino rats. The molecular, pharmacokinetic and toxicity properties of the synthesized compounds were calculated by Molinspiration and Osiris property explorer software. The results of in-vivo anti-inflammatory studies revealed that the compound. 4 showed maximum inhibition in paw edema volume followed by compound no. 3 while the compound no. 4 exhibited excellent  peripheral analgesic activity (74%) followed by the compound no. 5. Compound no. 4 and 5 also showed good central analgesic effect increased the reaction time to 90 minutes. All the title compounds except compound 5 are predicted to be safe by Osiris online software and are likely to have good oral bioavailability as they obey Lipinski’s rule of five for drug likeness

Transverse cerebellar diameter: a reliable predictor of gestational age

Objectives: To determine accuracy of transverse cerebellar diameter (TCD) measurement in the prediction of gestational age (GA) in normal fetuses; to develop reference chart for TCD according to GA in Indian population. Design: A retrospective cross-sectional study. Method: Ultrasonographic measurements in 300 singleton pregnant women included biparietal diameter (cm), head circumference (cm), abdominal circumference (cm), femur length (cm) and transverse cerebellar diameter (cm). Reference chart with mean TCD for corresponding gestational age (GA) in weeks was developed. Results: Statistically significant relationship found between TCD and gestational age (R2=0.92, p=0.0006). Regression formulae based on TCD with other parameter can be used to predict gestational age of foetus. When TCD is compared with findings in other studies in different ethnic population, it is found that there is significant difference exists. Conclusion: In normally developing fetuses the TCD has linear correlation with advancing gestational age. A separate reference chart is required for every different population because ethnicity, nutrition and environmental factors can have impact on normal TCD values. This will help to avoid misinterpretation of data to determine gestational age

In silico targeting enterotoxin from Staphylococcus aureus with selected flavonoids: Hope for the discovery of natural anti-mastitis agents

Staphylococcus aureus is a facultative anaerobe and catalase-positive bacterium responsible for various skin infections and life-threatening problems, including bacteremia and pneumonia. This bacterium produces a bunch of superantigens in the blood called enterotoxin. This toxin is responsible for food poisoning and toxic shock syndrome. Moreover, Bovine mastitis is also associated with S. aureus. Further, S. aureus related to drug resistance makes the infection more dreadful. Now a day, various natural compounds such as phytochemicals are gaining importance as they are effective against many diseases, including S. aureus infections. The present study used molecular docking of three ligands, i.e., Kaempferol, Apigenin, and Quercetin, with enterotoxin A from S. aureus. The docking study revealed that the binding energy of ligands with receptors was -6.6 to -6.9 Kcal/mol. Kaempferol had the highest binding affinity of -6.9 Kcal/mol, suggesting it has a potential against S. aureus. Therefore, in the current research, we have tried to identify occurring compounds that might be used to develop an effective anti-S.aureus agent. The findings are encouraging and will aid researchers in creating new mastitis-fighting medications based on natural phytochemicals

In silico targeting of osmoporin protein of Salmonella to identify anti-Salmonellosis phyto-compounds

Salmonella enterica serotype typhi is a gram-negative, rod-shaped bacterium, and has flagella with the human body as its only reservoir. Typhoid fever was found to cause 21.7 million illnesses and 216,000 fatalities worldwide in 2000, and the International Vaccine Institute estimated 11.9 million cases and 129,000 deaths in low- and middle-income countries in 2010. More than 10 million patients were infected with S. typhi each year and the mortality rate is associated with more than 0.1 million patients. Moreover, it is also associated with drug resistance globally which makes the disease more dreadful. Other than antibiotics, various flavonoids showed medicinal effects against many diseases including S. typhi infection. Flavonoids are a type of plant bioactive metabolite that have potential medicinal efficacy. The goal of this study was to see if certain flavonoids (ellagic acid, eriodictyol, and naringenin) could interact with the outer membrane of osmoporin (PDB ID: 3uu2) receptor in Salmonella and helps in inhibiting its growth. To look for probable ligand-receptor binding relationships, we used Pyrxmolecular docking software. The molecular docking results were analyzed using the Biovia discovery studio visualizer. The current study discovered that selected plant-based compounds interacted with an outer membrane of the osmoporin receptor, resulting in minimization of energy in the range of-6.6 to -7.8 Kcal/mol

Clinical outcome, viral response and safety profile of chloroquine in COVID-19 patients — initial experience

Introduction: Chloroquine and its analogues are currently being investigated for the treatment and post exposure prophylaxis of COVID-19 due to its antiviral activity and immunomodulatory activity.Material and methods: Confirmed symptomatic cases of COVID-19 were included in the study. Patients were supposed to receive chloroquine (CQ) 500 mg twice daily for 7 days. Due to a change in institutional protocol, initial patients received chloroquine and subsequent patients who did not receive chloroquine served as negative controls. Clinical effectiveness was determined in terms of timing of symptom resolution and conversion rate of reverse transcriptase polymerase chain reaction (RT-PCR) on day 14 and day 15 of admission.Results: Twelve COVID-19 patients formed the treatment arm and 17 patients were included in the control arm. The duration of symptoms among the CQ treated group (6.3 ± 2.7 days) was significantly (p-value = 0.009) lower than that of the control group (8.9 ± 2.2 days). There was no significant difference in the rate of RT-PCR negativity in both groups. 2 patients out of 12 developed diarrhea in the CQ therapy arm.  Conclusion: The duration of symptoms among the treated group (with chloroquine) was significantly lower than that of the control group. RT-PCR conversion was not significantly different between the 2 groups

Modelling small-scale storage interventions in semi-arid India at the basin scale

There has been renewed interest in the performance, functionality, and sustainability of traditional small-scale storage interventions (check dams, farm bunds and tanks) used within semi-arid regions for the improvement of local water security and landscape preservation. The Central Groundwater Board of India is encouraging the construction of such interventions for the alleviation of water scarcity and to improve groundwater recharge. It is important for water resource management to understand the hydrological effect of these interventions at the basin scale. The quantification of small-scale interventions in hydrological modelling is often neglected, especially in large-scale modelling activities, as data availability is low and their hydrological functioning is uncertain. A version of the Global Water Availability Assessment (GWAVA) water resources model was developed to assess the impact of interventions on the water balance of the Cauvery Basin and two smaller sub-catchments. Model results demonstrate that farm bunds appear to have a negligible effect on the average annual simulated streamflow at the outlets of the two sub-catchments and the basin, whereas tanks and check dams have a more significant and time varying effect. The open water surface of the interventions contributed to an increase in evaporation losses across the catchment. The change in simulated groundwater storage with the inclusion of interventions was not as significant as catchment-scale literature and field studies suggest. The model adaption used in this study provides a step-change in the conceptualisation and quantification of the consequences of small-scale storage interventions in large- or basin-scale hydrological models