Technique for Measurement of Weld Resistance for AC Resistance Spot Welding via Instantaneous Phasor Measurement

The resistance measurement in the resistance spot welding (RSW), is an ongoing research topic. The high current flow during the welding process induces an electromagnetic field in the wires which are attached to the electrodes to measure tip voltage. This results an additional voltage drop which is proportional to the derivative of current. Also the presence of silicon controlled rectifier (SCR) in the welding power supply generates harmonics in both supply voltage and current. These issues together complicate the methods for resistance estimation. A set of simultaneous linear equations is derived for the on-line measurement of dynamic resistance and induced voltage constant by using the dynamic circuit analysis of weld setup. This can be solved to determine the weld resistance using instantaneous phasors measurements for the 1st, 3rd and 5th harmonics of current and measured voltage signals. The instantaneous phasor measurements for these desired harmonics are obtained by employing the following proposed method. In this thesis, a new method for the measurement of instantaneous phasor is proposed for the narrow band signals. The proposed algorithm is based on the internal model principle (IMP) defined for the cancellation of a sinusoidal disturbance signal. The IMP has two states, exhibiting the properties of being sinusoidal and orthogonal. The instantaneous values of IMP states are defined as real and imaginary components of a complex signal at each time instant. The instantaneous measurements of envelope and phase of a sinusoidal signal are determined from instantaneous values of complex signal by using arithmetic properties of complex numbers. In case of signal comprising of sum of sinusoids of different frequencies, the approach for obtaining instantaneous phasor for each sinusoidal component is presented by connecting multiple internal models in the parallel and open-loop configuration. The instantaneous phasor measurement of fundamental frequency signal is not only advantageous in detecting faults like short circuiting, harmonic distortion and frequency variations but it can also be applied to protect power system from these faults. In this work, the applicability of the proposed instantaneous phasor measurement algorithm is analyzed for scenarios of power disturbances due to the the harmonic distortion and decaying DC offset. The results are discussed and compared with few existing methods

In Vitro Screening for Antioxidant and Anticholinesterase Effects of Uvaria littoralis Blume.: A Nootropic Phytotherapeutic Remedy

Background: Oxidative stress is strongly linked in the development of numerous chronic and degenerative disorders. Medicinal plants with antioxidant and anticholinesterase activities exert a key role for the management of oxidative stress related disorders mainly Alzheimer's disease (AD). Therefore the purpose of this study was to assess antioxidant potentiality and anticholinesterase inhibitory activity of crude methanolic extract (CME), petroleum ether fraction (PEF), chloroform fraction (CLF), ethyl acetate fraction (EAF) and aqueous fraction (AQF) of Uvaria littoralis (U. littoralis) leaves. Methods: The antioxidant compounds namely total flavonoids contents (TFCs) and total proanthocyanidins contents (TPACCs) were determined for quantities constituent’s characterization. Antioxidant capacity of U. littoralis leaves were estimated by the iron reducing power (IRPA), 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and nitric oxide (NO) radical scavenging capacity. Anticholinesterase effects were estimated for acetylcholinesterase (AChE) and butyrylcholinestrase (BChE) activity. Results: The EAF of U. littoralis leaves showed the highest TFCs as compared to CLF, CME, PEF and AQF. TPACCs were also found highest in EAF. The highest absorbance for IRPA was found in EAF (2.220 nm) with respect to CME and other fractions at the highest concentration. The EAF showed best DPPH and NO radical scavenging activity with IC50 values of 31.63 and 55.47 μg/mL, respectively with regard to CME and remaining fractions. The PEF represents highest AChE inhibitory activity with IC50 values of 35.19 μg/mL and CLF showed highest BChE inhibitory activity with IC50 values of 32.49 μg/mL. Conclusions: The findings of the current study demonstrate the presence of antioxidant phytochemicals, likewise, turns out antioxidant and anticholinesterase potentiality of U. littoralis leaves which could be a prestigious candidate for the treatment of neurodegenerative diseases especially AD

Co-morbidities in Patients Presenting with Gout at Tertiary Care Hospital Peshawar, A Cross Sectional Study, 2021 Pakistan

Background: Gout is one of the most prevalent inflammatory arthritis in the world. It is associated with non-modifiable factors like age gender and genetics and modifiable risk factors like life style changes. Objective: To determine the co-morbidities of gout in patients presenting at tertiary care hospital Peshawar. Study type, settings & duration: A descriptive cross sectional study was conducted at Department of Rheumatology, Lady Reading Hospital, Peshawar from January 2021 to August 2021. Methodology: In this study a total of 323 patients fulfilling the inclusion and exclusion criteria of Gout were observed. All the patients in age between 16-80 years, either gender presenting with gout were included in the study. Gout was diagnosed as per American College of Rheumatology (ACR) Gout Classification Criteria.All the information i.e. age, gender and comorbidities were recorded and were analyzed in statistical software SPSS version 23. Results: A total of 323 patients were enrolled in the study, mean age was 42 with SD ±12.49,female predominance was noted with percentage of 71.8%.The most common comorbidities associated with gout were hypertension(61.6%) and obesity (68.1%). We had patients with other co-existing inflammatory and non-inflammatory Rheumatological diseases. These included seropositive and seronegative Rheumatoid arthritis, Polymyalgia Rheumatica PMR, connective tissue disorder CTD and psoriasis were rarely reported. Among non-inflammatory RMDs, vitamin D deficiency was found to be highly prevalent, followed by Osteoarthritis, Spondylitis and Radiculopathies. Conclusion: Our study concludes that the most common co-morbidities of gout were hypertension and obesity followed by other Rheumatologic diseases (RMDs) and vitamin D deficiency

Co-morbidities in Patients Presenting with Gout at Tertiary Care Hospital Peshawar, A Cross Sectional Study, 2021 Pakistan

Background: Gout is one of the most prevalent inflammatory arthritis in the world. It is associated with non-modifiable factors like age gender and genetics and modifiable risk factors like life style changes. Objective: To determine the co-morbidities of gout in patients presenting at tertiary care hospital Peshawar. Study type, settings & duration: A descriptive cross sectional study was conducted at Department of Rheumatology, Lady Reading Hospital, Peshawar from January 2021 to August 2021. Methodology: In this study a total of 323 patients fulfilling the inclusion and exclusion criteria of Gout were observed. All the patients in age between 16-80 years, either gender presenting with gout were included in the study. Gout was diagnosed as per American College of Rheumatology (ACR) Gout Classification Criteria.All the information i.e. age, gender and comorbidities were recorded and were analyzed in statistical software SPSS version 23. Results: A total of 323 patients were enrolled in the study, mean age was 42 with SD ±12.49,female predominance was noted with percentage of 71.8%.The most common comorbidities associated with gout were hypertension(61.6%) and obesity (68.1%). We had patients with other co-existing inflammatory and non-inflammatory Rheumatological diseases. These included seropositive and seronegative Rheumatoid arthritis, Polymyalgia Rheumatica PMR, connective tissue disorder CTD and psoriasis were rarely reported. Among non-inflammatory RMDs, vitamin D deficiency was found to be highly prevalent, followed by Osteoarthritis, Spondylitis and Radiculopathies. Conclusion: Our study concludes that the most common co-morbidities of gout were hypertension and obesity followed by other Rheumatologic diseases (RMDs) and vitamin D deficiency

Knowledge, beliefs, attitudes and perceived risk about COVID-19 vaccine and determinants of COVID-19 vaccine acceptance in Bangladesh

Bangladesh govt. launched a nationwide vaccination drive against SARS-CoV-2 infection from early February 2021. The objectives of this study were to evaluate the acceptance of the COVID-19 vaccines and examine the factors associated with the acceptance in Bangladesh. In between January 30 to February 6, 2021, we conducted a web-based anonymous cross-sectional survey among the Bangladeshi general population. At the start of the survey, there was a detailed consent section that explained the study’s intent, the types of questions we would ask, the anonymity of the study, and the study’s voluntary nature. The survey only continued when a respondent consented, and the answers were provided by the respondents themselves. The multivariate logistic regression was used to identify the factors that influence the acceptance of the COVID-19 vaccination. A total of 605 eligible respondents took part in this survey (population size 1630046161 and required sample size 591) with an age range of 18 to 100. A large proportion of the respondents are aged less than 50 (82%) and male (62.15%). The majority of the respondents live in urban areas (60.83%). A total of 61.16% (370/605) of the respondents were willing to accept/take the COVID-19 vaccine. Among the accepted group, only 35.14% showed the willingness to take the COVID-19 vaccine immediately, while 64.86% would delay the vaccination until they are confirmed about the vaccine’s efficacy and safety or COVID-19 becomes deadlier in Bangladesh. The regression results showed age, gender, location (urban/rural), level of education, income, perceived risk of being infected with COVID-19 in the future, perceived severity of infection, having previous vaccination experience after age 18, having higher knowledge about COVID-19 and vaccination were significantly associated with the acceptance of COVID-19 vaccines. The research reported a high prevalence of COVID-19 vaccine refusal and hesitancy in Bangladesh. To diminish the vaccine hesitancy and increase the uptake, the policymakers need to design a well-researched immunization strategy to remove the vaccination barriers. To improve vaccine acceptance among people, false rumors and misconceptions about the COVID-19 vaccines must be dispelled (especially on the internet) and people must be exposed to the actual scientific facts

Knowledge, attitude, and practices toward food safety among students in Bangladesh: A cross-sectional web-based study

Background: Foodborne diseases are a preventable but under-reported public health issue. These illnesses are a public health concern and contribute significantly to healthcare costs. People must understand how their knowledge, attitudes, and practices affect food safety and how they can reduce the risk of foodborne illness. This study aimed at investigating the current situation of knowledge, attitudes, and practices toward food safety among Bangladeshi students and identifying the determinants of having adequate knowledge, favorable attitudes, and good practices. Methods: The research is based on a cross-sectional anonymous online survey that took place from January 1st to February 15th, 2022. Participants in this survey had to be at least 8th-grade students enrolled in Bangladeshi institutions. Upon description of the study's aim, the questionnaire's concept, assurances regarding respondents' confidentiality, and the study's voluntary nature, informed consent was taken from each participant before starting the survey. Descriptive statistics, Chi-square test, and logistic regression were used to explore the knowledge, attitudes, and practices of students and identify factors affecting them using the statistical software STATA. Results: A total of 777 students participated in the study, the majority of them were male (63.96%) and aged between 18 and 25 years (60%). Almost half of the respondents were at the undergraduate level and less than half of the participants (45%) lived with their families. Among the participants, around 47% had adequate knowledge, 87% had favorable attitudes, and only 52% had good practices toward food safety. Female students, students having a food safety course/training, and students whose mothers were educated had significantly higher knowledge of food safety. Besides, students at higher education levels, students having a food safety course/training, and students with educated mothers displayed significantly higher odds of possessing favorable attitudes toward food safety. Similarly, female students, having a food safety course/training, students at higher education levels, and students with educated mothers were significantly associated with good practices toward food safety among students. Conclusion: The study shows that students in Bangladesh lack knowledge of food safety and have poor practices toward food safety. For the student population of Bangladesh, more systematic and targeted food safety education and training are required

Suppression of human prostate cancer cell growth by forced expression of connexin genes

The cell‐to‐cell channels in gap junctions, formed of proteins called connexins (Cxs), provide a direct intercellular pathway for the passage of small signaling molecules (≤1 kD) between the cytoplasmic interiors of adjoining cells. It has been proposed that alteration in the expression and function of Cxs may be one of the genetic changes involved in the initiation of neoplasia. To elucidate the role of Cxs in the pathogenesis of human prostate cancer (PCA), the pattern of expression of Cx α1 (Cx43) and Cx β1 (Cx32) was studied by immunocytochemical analysis in normal prostate and in prostate tumors of different histological grades. While normal prostate epithelial cells expressed only Cx β1, both Cx α1 and Cx β1 were detected in PCA cells. The Cxs were localized at the cell–cell contact areas in normal prostate and well‐differentiated prostate tumors; however, as prostate tumors progressed to more undifferentiated stages, the Cxs were localized in the cytoplasm, followed by an eventual loss in advanced stages. Thus, epithelial cells from prostate tumors showed subtle and gross alterations with regard to expression of Cx α1 and Cx β1 and their assembly into gap junctions during the progression of PCA. Retroviral‐mediated transfer of Cx α1 and Cx β1 into a Cx‐deficient human PCA cell line, LNCaP, inhibited growth, retarded tumorigenicity, and induced differentiation, and these effects were contingent upon the formation of gap junctions. In addition, the capacity to form gap junctions in most Cx‐transduced LNCaP cells was lost upon serial passage. Taken together, these findings indicate that the control of proliferation and differentiation of epithelial cells in prostate tumors may depend on the appropriate assembly of Cx β1 and Cx α1 into gap junctions and that the development of PCA may involve the positive selection of cells with an impaired ability to form gap junctions. Dev. Genet. 24:91–110, 1999. © 1999 Wiley‐Liss, Inc