Detection of Aliphatically Bridged Multi-Core Polycyclic Aromatic Hydrocarbons in Sooting Flames with Atmospheric-Sampling High-Resolution Tandem Mass Spectrometry.

This paper provides experimental evidence for the chemical structures of aliphatically substituted and bridged polycyclic aromatic hydrocarbon (PAH) species in gas-physe combustion environments. The identification of these single- and multicore aromatic species, which have been hypothesized to be important in PAH growth and soot nucleation, was made possible through a combination of sampling gaseous constituents from an atmospheric pressure inverse coflow diffusion flame of ethylene and high-resolution tandem mass spectrometry (MS-MS). In these experiments, the flame-sampled components were ionized using a continuous VUV lamp at 10.0 eV and the ions were subsequently fragmented through collisions with Ar atoms in a collision-induced dissociation (CID) process. The resulting fragment ions, which were separated using a reflectron time-of-flight mass spectrometer, were used to extract structural information about the sampled aromatic compounds. The high-resolution mass spectra revealed the presence of alkylated single-core aromatic compounds and the fragment ions that were observed correspond to the loss of saturated and unsaturated units containing up to a total of 6 carbon atoms. Furthermore, the aromatic structures that form the foundational building blocks of the larger PAHs were identified to be smaller single-ring and pericondensed aromatic species with repetitive structural features. For demonstrative purposes, details are provided for the CID of molecular ions at masses 202 and 434. Insights into the role of the aliphatically substituted and bridged aromatics in the reaction network of PAH growth chemistry were obtained from spatially resolved measurements of the flame. The experimental results are consistent with a growth mechanism in which alkylated aromatics are oxidized to form pericondensed ring structures or react and recombine with other aromatics to form larger, potentially three-dimensional, aliphatically bridged multicore aromatic hydrocarbons

Modelling And Experimental Vibration Control Of A Two-link Three-dimensional Manipulator With Flexible Links

Current industrial and space manipulators are required to achieve higher speeds in a lighter structure without sacrificing payload capabilities. Consequently, undesirable vibration occurs during the motion. By suitable modelling of the manipulator flexibility, advanced control strategies can be formulated to improve the joint tracking performance and reduce the residual vibration of the end-point in the presence of payload uncertainties.;Toward this goal, an experimental two-link, 3D, anthropomorphic manipulator with flexible links was designed and built to be used as a test bed for the verification and refinement of the proposed modelling and control strategies.;The nonlinear equations of motion for the robot were derived using Lagrangian dynamics. The model was verified using experimental modal analysis techniques. Based on experimental results, a simplified nonlinear model, that contains the relevant modes of the system, was derived and subsequently used in controller designs and state estimation.;A conventional Proportional-plus-Derivative (PD) controller that implements joint angles feedback was designed to be used as a baseline controller due to its wide applicability on industrial manipulators.;By measuring the links tip vibration using accelerometers, several adaptive controllers and state observers were designed and implemented successfully on the manipulator, namely, a gain-scheduling linear quadratic regulator, a model reference adaptive controller, an adaptive inverse dynamics controller, a least-squares nonlinear state estimator and a robust sliding observer. The controllers performance and robustness were tested and experimentally verified against the change of the payload.;The control strategies and identification techniques, developed in this thesis, are applicable to a wide range of robot manipulators including industrial manipulators

Detection of bla SHV and bla CTX-M genes in ESBL producing Klebsiella pneumoniae isolated from Egyptian patients with suspected nosocomial infections

The correct identification of the genes involved in ESBL mediated  resistance is necessary for the surveillance and epidemiological studies of their transmission in hospitals. The aim of the present study was to find the prevalence of ESBL producing Klebsiella pneumoniae among K. pneumoniae isolates separated from Egyptian patients with suspected nosocomial infections, to detect their drug resistance pattern and to look for bla SHV and bla CTX-M genes in such organisms.Subjects and methods: 138 K. pneumoniae isolates from Egyptian patients with suspected nosocomial infections were screened for ESBL production by the pattern of antimicrobial susceptibilities. Phenotypic identification for ESBL production was confirmed by double disc synergy test, phenotypic confirmatory double disc test and by MicroScan panel system. bla SHV and bla CTX-M genes in ESBL producing K. pneumoniae were detected using multiplex PCR. Results: The prevalence of ESBL producing K. pneumoniae was 21% (30/138). Their pattern of antimicrobial susceptibility showed that 90% was resistant to (Sulphamethoxazole/Trimethoprim), 70% was resistant to(Amoxicillin/Clavulanate), 63.3% was resistant to Cefotaxime and Ceftazidime, 60% was resistant to Amikacin, 46.7% was resistant to Doxycycline, Cefoxitin, Ceftriaxone and Levofloxacin, 40% was resistant to Cefepime, 20% was resistant to Ertapenem and  (Sulbactam/Cefoperazone), 13.3% was resistant to (Piperacillin/Tazobactam), 10% was resistant to (Imipenem/Cilastatin) and Gentamycin and 6.7% was resistant to Meropenem and Ciprofloxacin. Among the ESBL producing K. pneumoniae, three out of 30 (10%) and 16 out of 30 (53.3%) were positive for bla SHV and bla CTX-M genes respectively. It could be concluded that ESBL producing isolates of K. pneumoniae have been increasingly recognized in the hospital settings in Egypt and are associated with multiple drug resistance. Thus, molecular identification of the genes encoding beta lactamases would be essential for a reliable epidemiological investigation of their transmission in hospitals and antimicrobial resistance

A molecular target for viral killer toxin: TOK1 potassium channels.

Killer strains of S. cerevisiae harbor double-stranded RNA viruses and secrete protein toxins that kill virus-free cells. The K1 killer toxin acts on sensitive yeast cells to perturb potassium homeostasis and cause cell death. Here, the toxin is shown to activate the plasma membrane potassium channel of S. cerevisiae, TOK1. Genetic deletion of TOK1 confers toxin resistance; overexpression increases susceptibility. Cells expressing TOK1 exhibit toxin-induced potassium flux; those without the gene do not. K1 toxin acts in the absence of other viral or yeast products: toxin synthesized from a cDNA increases open probability of single TOK1 channels (via reversible destabilization of closed states) whether channels are studied in yeast cells or X. laevis oocytes

Cytolethal distending toxin (CDT)-negative Campylobacter jejuni strains and anti-CDT neutralising antibodies induced during human infection but not chicken colonisation

The cytolethal distending toxin (CDT) of Campylobacter jejuni was detectable, using an in vitro assay, in most but not all of 24 strains tested. The reason for the absence of toxin activity in these naturally occurring CDT-negative C. jejuni strains was then investigated at the genetic level. CDT is encoded by three highly conserved genes, cdtA, -B, and -C. In the CDT-negative strains, two types of mutation were identified. The CDT activities of C. jejuni strains possessing both types of mutation were successfully complemented with the functional genes of C. jejuni 11168. The first type of mutation comprised a 667-bp deletion across cdtA and cdtB and considerable degeneration in the remainder of the cdt locus. Using a PCR technique to screen for this deletion, this mutation occurred in fewer than 3% of 147 human, veterinary, and environmental strains tested. The second type of mutation involved at least four nonsynonymous nucleotide changes, but only the replacement of proline with serine at CdtB position 95 was considered important for CDT activity. This was confirmed by site-directed mutagenesis. This type of mutation also occurred in fewer than 3% of strains as determined using a LightCycler biprobe assay. The detection of two CDT-negative clinical isolates raised questions about the role of CDT in some cases of human campylobacteriosis. To determine if anti-CDT antibodies are produced in human infection, a toxin neutralization assay was developed and validated using rabbit antisera. Pooled human sera from infected patients neutralized the toxin, indicating expression and immunogenicity during infection. However, no neutralizing antibodies were detected in colonized chickens despite the expression of CDT in the avian gut as indicated by reverse transcription-PCR

Detection of occult HBV infection by nested PCR assay among chronic hepatitis C patients with and without hepatocellular carcinoma

Occult hepatitis B virus infection (OBI) has been reported among patients with chronic hepatitis C virus (HCV) infection and hepatocellular carcinoma (HCC). This study aimed to evaluate the prevalence of OBI in chronic hepatitis C patients with and without hepatocellular carcinoma. A total of 40 chronic hepatitis C patients who were negative for HBsAg, were enrolled into the study. They were classified into two groups: Group I which included 20 patients with chronic hepatitis C only whereas Group II included 20 patients with chronic hepatitis C and HCC. Detection of HBV DNA was done by nested-PCR using two sets of primers specific for surface and X viral genomes in serum and liver tissue of patients. Genotyping system based on PCR using type-specific primers was done for HBV-DNA positive intrahepatic samples. OBI was detected in the liver tissue in 23/40 (57.5%) of chronic HCV infected patients, 18 (78.3%) of whom belonged to group II, conferring a 90% prevalence of this group. In serum, HBV-DNA was detected in 9/40 patients (22.5%), 7 (77.8%) of whom belonged to group II. Among the 23 positive intrahepatic HBV-DNA samples studied, HBV-genotype D (34.8%) and B (26.1%) were more predominant, whereas HBV-genotype C (13.1%) and A (8.7%) infections were the least observed, respectively; mixed genotypes were detected in 17.4% (n= 4), 3 of them were with HBV-genotype D and B, and 1 was with HBV-genotype C and A. In conclusion OBI is a fact in our community; it was detected in liver tissue of chronic HCVinfected patients, especially in cases of chronic HCC. In addition, OBI might be related to severity of necroinflammatory activity and fibrosis. Large studies are needed to confirm that co-infection could determine a worse progress of chronic liver disease in this population. Also, detection of intrahepatic HBV-DNA is more useful in diagnosis of OBI.Keywords: Occult hepatitis B virus infection (OBI); Chronic hepatitis C virus infection (CHC); Hepatocellular carcinoma (HCC); HBV-DNA; Nested PC

Effect of low protein diet supplemented with or without amino acids on the production of broiler

Experiment was carried out to investigate the effect of low protein diet supplemented with or without amino acids on the performance of broiler. Hubbard 375 day-old broiler were purchased, initially weighed and randomly divided into five groups (75 broilers in each group). Group A was kept as control given commercial feed, group B further divided into two group B1 and B2 were fed low CP (15 and 16%) ratio supplemented with lysine (1.0%) and methionine (0.5%) , while group C also further divided into group C1 and C2 were fed with the same low CP(15 and 16%) ratio without lysine and methionine supplementation. The experimental ratios were start up from fourth week of the experiment. Feed intake of broiler in group A, B1, B2, C1 and C2 was 3.793, 3.781, 3.739, 3.837 and 3.852 kg/b,(P > 0.05) and water intake 11.113, 11.494, 11.850, 11.277 and 11.252 lit/b, (P > 0.05), respectively. Live body weight of broiler was higher in B1 (2.149), than A(2.091), B2(2.069), C1(1.952) and C2(1.929), kg/b (P < 0.05) and their FCR was better for B1(1.75) than B2(1.80), A(1.81), C1(1.85) and C2(1.99), respectively. Carcass weight of broiler for A (1.227), B1 (1.339), B2 (1.210), C1 (1.155) and C2 (1.200) kg/b, (P > 0.05) and their dressing percentage were A(60.46), B1 ( 62.41), B2(60.48), C1 (59.59) and C2(59.22) percent (P > 0.05), respectively. Mortality of broiler in group A (5.3), B1 (2.6), B2 (6.6), C1 (4.0) and C2 (1.3) percent (P > 0.05), respectively. The average weight of liver, heart, gizzard, spleen and intestine for various group of broiler were found non significant (P > 0.05). Net profit was better in group B1 (75.5), followed by B2 (68.3), A (62.5), C1 (51.8) and C2 (49.9) Rs/b, respectively. It was concluded that low protein diet supplemented with lysine plus methionine significantly improved live body weight of broiler.Key words: Protein, amino acid, supplemented, broiler

In vivo pathogenicity of hydropericardium hepatitis syndrome (Angara disease)

This study was conducted on 175 one day old broiler chicks in order to observe in vivo pathogenicity of hydropericardium hepatitis syndrome (Angara disease). Chicks were grouped into A (25 chicks; reared at the Poultry Research institute (PRI), Rawalpindi) and B groups (150 chicks; reared at National Veterinary Laboratories (NVL) Islamabad in poultry rearing units). Feed and water were provided adlibitum to all the birds in both groups. The LD50 (lethal dose 50) of the virus was determined at the age of 26 days of broiler chickens divided into sub-groups a, b, c, d and e (each having 5 birds). The LD50 titre of the viral suspension (10%) was prepared from liver extract and determined as 10-2.5 per ml. During the study, potency of the vaccines was determined by vaccinating 150 chicks of sub-group k, l, m, n and o (each having 30 birds) with a dose of 0.2 ml. The vaccinated and non-vaccinated chicks of sub-groups were challenged with viral dose of 2 ml at day 17 post-vaccination to know the protection potency of the vaccines. No chick showed clinical manifestation of disease up to five days post challenge. On the 6th day post challenge, all the chicks were slaughtered and subjected to postmortem. Some of the chicks showed the lesions of hydropericarium. Histopathological findings of liver of all sub-groups revealed different stages of necrosis, cloudy swelling, liquefactive necrosis, cytoplasmic blabing, fatty degeneration and intranuclear inclusion bodies of virus.Key words: In vivo pathogenicity, hydropericardium hepatitis syndrome, Angara disease

An inverted virtual faculty development program for remote teaching: pilot for replication

Background: Due to the COVID 19 pandemic, all the universities worldwide are experiencing a paradigm shift to online learning. Baby boomers and Generation X need to cope with the challenging transformation, so an emerging need for a faculty development program was needed towards achieving the goal of that transformation. Objectives: To describe and assess an inverted virtual faculty development program (VFDP) that was designed and implemented for the first time in the school to equip educators with the necessary technology competencies for remote online learning. Methods: An interventional prospective study held in a university setting post need analysis conduction to prioritize the required technological skills for faculty members. The program was designed to integrate five essential skills needed to by faculty members to teach remotely. The intervention comprised attending five virtual sessions after watching a pre-distributed material, then evaluated using the Kirkpatrick model.Results: Almost 81% of faculty members completed the program and 80 % of participants were satisfied with the content of the program. There was a statistically significant difference between the perceived ability of the participants to share and record video lectures before and after the VFDP (p value <0.001). The percentage of the departments that applied the program components showed that 96% of them were able to record lectures. In addition, 80% of them were able to develop online quizzes. Conclusion: The inverted virtual faculty development program (VFDP) has supported the participating faculty in developing their needed technological competencies required to bridge the gap of remote teaching/learning

Clinical Profile of Patients with Osteoarthritis of the Knee A Study of 162 Cases

One hundred sixty two patients of osteoarthritis (OA)knee were studied to describe their clinical profile. Thepatients were included according to the criteria developedby the American College of Rheumatology. Detailedhistory, clinical examination and X-rays were carried out.The data were analysed statistically and the results wereexpressed in percentage and frequency. In this study, 96(59.3%) were male and 66 (40.7%) were female. Themean age of the subject was 53.73 ± 11.35 years. Mostof the patients of were in the age group of 50 to 59 years.Maximum number of females in the age group of 35 to45 years was affected. Most of the males were affectedin the later ages, between 55 to 65 years. Most of thepatients were middle class (68.5%) and housewives(35.8%). Mean height was 159.99 ± 8.12 cm and meanweight was 63.34 ± 11.60 kg. Mean duration of symptomswas 25.25 ± 38.85 months. Most patients gave the historyof gradual onset of the pain (87.7%). Most of the patientshad no morning stiffness in the knee (90.1%). Morningstiffness was present in 9.3% but it was for less than onehour. Maximum patients had intermittent pain (53.7%)but 46.3% patients had constant pain. By this study, itcan be concluded that OA knee is commoner in malesbut females develop it earlier in the life than the males