Protection of nitrogenase levels in dark-incubated cultures of Anabaena sp. strain CA by various carbon sources, and restoration of nitrogenase activity by oxygen

Photoautotrophically grown, nitrogen-fixing cultures of Anabaena sp. strain CA lost nitrogenase activity completely after 4 h of incubation in the dark. The original level of nitrogenase activity was restored within 3 h of re-illumination and was apparently dependent on de novo protein synthesis. Several organic carbon sources protected nitrogenase activity. The heterocysts isolated from photoautotrophically grown cultures incubated in the dark (35 min) showed negligible nitrogenase activity. When these heterocysts were exposed to oxygen, glucose or fructose during isolation, normal activity was observed only with O2. Oxygen also enhanced the rate of initial H2 evolution from isolated heterocysts

Effects of some inhibitors and carbon sources on acetylene reduction and hydrogen production of isolated heterocysts of Anabaena sp. (strain CA)

Metabolically active heterocysts isolated from wild-type Anabaena sp. strain CA showed high rates of light dependent acetylene reduction and H2 evolution. Fructose and erythrose significantly stimulated nitrogenase activity but not H2 evolution. DCMU and cyanide were not effective. DBMIB significantly inhibited both nitrogenase and nitrogenase-catalysed H2 evolution. This inhibition was overcome by a catalytic amount of TMPD. These data suggest that in the isolated heterocysts all electrons, irrespective of source, must pass through the plastoquinone pool before reducing ferredoxin, which in turn can reduce dinitrogen to ammonia

Role of cephalomedullary nail in proximal femur fractures

Background: Hip fractures are recognized to be a major public health problem. Key determinants of hip fractures include age, osteoporosis, and falls. In these determinants socioeconomic status, have not been well explored. Under eccentric loading, high bending loads occur, leading to failure of the osteosynthetis anchorage at the center of the femoral head.The introduction of the reconstruction nail has broadened the indications for the intramedullary fixation of difficult femoral fractures. The operative technique is however complicated. Some technical difficulties encountered during its use are presented together with guidance to allow these problems to be avoided.Methods: This Study had included 47 cases which were operated by single surgeon and use of different implant (cephalomedullary nail) was randomized irrespective of fracture types and pattern. This study was done over a period of 12 months (October 2013 to October 2014) with 1 month, 3 months, 6 months, 12 months follow up. At every visit patient were assessed as per Oxford hip score. Type of implant used was PFNA, Intertan, Sirus Nail.Results: The mean age of the patients was 65.68 (±13.55) years. Severe pain was observed among majority of the patients at one month (70.2%) which became mild (40.4%) and moderate (34%) at 3 months. Very mild pain was found in 36.2% patients at 6 months and in 61.7% at 12 months. The limping was all the time among all the patients at one month. However, the limping was found often in 46.8% at 3 months and sometimes in 57.4% at 6 months and 53.2% at 12 months. The hip score was found to be severe among all the patients at one month. However, moderate to severe hip was in 46.8% patients at 3 months, mild to moderate was in 57.4% at 6 months and satisfactory joint function was in 68.1% at 12 months. The comparison of Hip score according to long or short nail at one 3, 6 and 12 months showed no difference. Conclusions: Cephalomedullary nails with adequate technique so that the lag screws by purchase in the centre-centre or posterior-inferior quadrant combines the benefit of sliding hip screw as well as intramedullary implants. So we recommend the use of cephalomedullary nails in proximal femur fractures especially the unstable fractures

Role of Interferon in Cancer Metabolism

Interferons (IFNs), a pleotropic cytokine that has long been regarded as an important effector molecule, are increasingly recognized due to their role in cancer and in antitumor immune response regulation. Interferons broadly alter cellular functions in response to viral and other infections. Dysregulation of interferon has been implicated in cancer, autoimmune disorders, and pathogenesis of chronic viral infections. However, the association between interferons and cancer cell metabolism is poorly understood. Emerging evidence suggests the importance of lipid, energy, and amino acid metabolic pathway in regulating interferon response against cancer. Additionally, viruses exploit and modulate the host cell and induce the major metabolic reprogramming causing cancer. In response, interferons upregulate the transcription of large number of interferon stimulating gene (ISG) whose products play a major role in the innate and adaptive immune response against viral infection. Immense research is being done on understanding the role of IFNs in cancer metabolism. Therefore, systematic evaluation of these associations between interferons and cancer metabolism may have important implications for the development of anticancer therapeutics targeting IFN, minimizing toxicity, and limiting off-target effects

In silico analysis of c-Met expression and its correlation with metabolic network in head and neck cancer

Background: Head and Neck Squamous Cell Carcinoma (HNSCC) is strongly associated with metabolic dysregulations. c-Met activation is important for high glucose induced acquisition of mesenchymal phenotype, survival under high glucose stress in HNSCC cells. Here, we utilise the In silico approach to analyse the c-Met expression in the head and neck cancer data extracted from The Cancer Genome Atlas (TCGA) database and its strong correlation with genes associated with cancer cell metabolism. Methods: In the current study, our investigations were performed using different bioinformatics tools and databases, including GEPIA (a webserver which extracts data from the Cancer Genome Atlas (TCGA) data portal and the GTEx database of normal tissues. http://gepia.cancer-pku.cn), and STRING databases (functional protein association networks (https://string-db.org/). Results: Here, we report the upregulation of c-Met in HNSCC patient cases along with a significant upregulation of major metabolic genes such as GLUT-1, HK-II, LDH-A, MCT-1, PFK in the HNSCC patient cases as compared to normal samples obtained from TCGA databases. Moreover, the current study revealed the c-Met overexpression across the histological and molecular subtypes of different HNSCC patient cases. We also showed the possible association of c-Met expression between the metabolic gene expression in HNSCC patient samples. We showed that patients with higher expression of c-Met had a shorter overall survival time and worse prognosis, and c-Met higher-expression levels also resulted in worse disease free survival in many cancers, confirming the association of c-Met and metabolic related genes with poor clinical outcomes in HNSCC. Furthermore, the protein-protein network analysis identifies the co-expression of metabolic associated genes with the c-Met. Conclusions: Our analysis suggests the correlation with higher expression of c-Met with a shorter overall survival and worse prognosis of HNSCC patients. Furthermore, the proteinprotein network analysis identifies the co-expression of metabolic associated genes with the c-Met expression. Those genes with moderate and very strong positive correlations with cMet expression in cancers are involved in the glucose metabolism, lipid metabolism, cell cycle process. Considering c-Met inhibition in HNSCC would be an important strategy for therapy that may favour the sensitization of HNSCC through metabolic network

Backward Precessional Whip and Whirl for a Two Point Rubbing Contact Model of a Rigid Rotor Supported by an Elastically Supported Rigid Stator

The present work investigates the phenomena of whip and whirl for a rigid rotor contacting at two bearing locations. The idea originated from an anemometer consisting of a rotor with an elastically supported stator undergoing the phenomena of dry friction whip and whirl at the two bushing contacts. To analyze the behavior, a mathematical model similar to the anemometer is developed and analyzed assuming two possible solutions, Mode1 (normal reaction forces in phase at two contacts) and Mode 2 (normal reaction forces out of phase at two contacts). Analytical solutions are only possible for the models with same RCl (Radius to Clearance ratio) at the two rub locations. A simulation model is constructed using the Texas A&M University (TAMU) Turbomachinery Laboratory rotordynamics software suite XLTRC² comprised of Timoshenko beam finite elements to form multiple degrees of freedom rotor and stator models. The nonlinear connections at the rub surface are modeled using Hunt and Crossley‘s contact model with coulomb friction. Dry friction simulations are performed for three separate models depending on the rotor‘s mass disk location with respect to the contact locations. The three models used have (1) Disk at center location (2) Disk at 3/4 location (3) Disk at overhang location. The adequacy of the analytical solution is investigated using the above simulations. Also, cases are explored where the general assumed solution would not solve the mathematical model, e.g. different RCl ratios at the two contacts. Simulations are performed for increasing as well as decreasing running speeds. There is partial agreement between simulation predictions and the analytical solutions for the cases with the mass center at centered and at 3/4 location. First, whirl-to-whip transitions occur at near the combine rotor-stator bounce frequency for both disk at center and disk at 3/4 location. The case with overhang mass disk predicts the two contacts to whip and at different frequencies simultaneously. Neither of the analytical solutions predicts a case where precession occurs at two different frequencies at the two contact points. Predictions for models with different RCl on the Backward Precessional (BP) graph imitate whirling. The BP graph predicts increasing BP frequency with increasing rotor speeds which is a characteristic of whirling, whereas investigation of individual contact velocities suggest that they are slipping at all conditions, one of them slipping more than the other netting a whirling like motion. For the overhang model with different RCl, apart from whipping at different frequency the two contacts also whirl at different frequencies corresponding to the RCl at the respective contacts. Simulations for decreasing rotor speed predict jump down from whirl- to-whip different BP frequency as compared to the jump up from whip-to-whirl for the speed up

ContraDoc: Understanding Self-Contradictions in Documents with Large Language Models

In recent times, large language models (LLMs) have shown impressive performance on various document-level tasks such as document classification, summarization, and question-answering. However, research on understanding their capabilities on the task of self-contradictions in long documents has been very limited. In this work, we introduce ContraDoc, the first human-annotated dataset to study self-contradictions in long documents across multiple domains, varying document lengths, self-contradictions types, and scope. We then analyze the current capabilities of four state-of-the-art open-source and commercially available LLMs: GPT3.5, GPT4, PaLM2, and LLaMAv2 on this dataset. While GPT4 performs the best and can outperform humans on this task, we find that it is still unreliable and struggles with self-contradictions that require more nuance and context. We release the dataset and all the code associated with the experiments