Enzyme activity in terrestrial soil in relation to exploration of the Martian surface

Urease activity in soil is persistent for long periods under low water, low temperature, and sterile regimes, and it was suggested that some form of enzyme-protective mechanism exists in soil. Dublin soil was extracted by sonication in water followed by adding a mixture of salts. Urease activity is associated with the organo-mineral complex thus obtained and is resistant to the activities of proteolytic enzymes. Clay free soil organic matter prepared subsequently by filtration also exhibits urease activity which is resistant to proteolysis. Models consisting of enzymes with bentonite and lignin were found to mimic this resistance to proteolysis. A model system is presented which suggests both the origin and location of soil ureases and a reason for their persistence in nature

Quantitative Structure-Activity Relationship Analysis of the Anticonvulsant Activity of Some Benzylacetamides Based on Genetic Algorithm-Based Multiple Linear Regression

Purpose: To develop the quantitative structure-activity relationship (QSAR) for predicting the anticonvulsant activity of α-substituted acetamido-N-benzylacetamide derivatives.Methods: AM1 semiempirical quantum chemical calculation method was used to find the optimum 3D geometry of the studied molecules. Two types of molecular descriptors, including the 2D autocorrelation and GETAWAY descriptors, were used to derive a quantitative relation between anticonvulsant activity and structural properties. The relevant molecular descriptors were selected by genetic algorithm-based multiple linear regression (GA-MLR) approach.Results: The high value of the correlation coefficient, R2 (0.900), indicate that the model was satisfactory.Conclusion: The proposed model has good stability, robustness and predictability when verified by internal and external validation.Keywords: Anticonvulsant, Benzylacetamides, 2D Autocorrelation, Quantitative structure-activity relationships, Multiple linear regression

Bis(dimethylformamide-κO){4,4′,6,6′-tetrachloro-2, 2-[butane-1,4-diyl(nitrilomethanylylidene)]diphenolato-κ4O,N, N′,O′}nickel(II).

In the title Schiff base complex, [Ni(C18H14Cl 4N2O2)(C3H7NO) 2], the geometry around the NiII atom is distorted octahedral. It is coordinated by the N2O2 donor atoms of the tetradentate Schiff base ligand and the O atoms of two dimethylformamide molecules, which are cis to one another. The benzene rings are almost normal to each other [dihedral angle = 88.60 (14)°]. The various intramolecular C - H⋯O hydrogen bonds make S(5) and S(6) ring motifs. In the crystal, molecules are linked by pairs of weak C - H⋯Cl interactions, forming inversion dimers. © 2012 International Union of Crystallography

Aqua{4,4′,6,6′-tetra­chloro-2,2′-[(2,2-di­methylpropane-1,3-diyl)bis­(nitrilomethanylyl­idene)]diphenolato}zinc.

The asymmetric unit of the title compound, [Zn(C19H16Cl4N2O2)(H2O)], comprises two crystallographically independent mol­ecules. The geometry around the ZnII atoms is distorted trigonal–bipyramidal, supported by the N2O2 donor atoms of the tetradentate Schiff base and a coordinating water mol­ecule. The dihedral angles between the benzene rings in the two mol­ecules are 34.10 (15) Å and 30.61 (15) Å. In the crystal, neighbouring independent mol­ecules are linked by pairs of O—H⋯O hydrogen bonds, forming dimers with R22(6) ring motifs, and by O—H⋯Cl hydrogen bonds. There are short Cl⋯Cl [3.4728 (16), 3.4863 (16), and 3.388 (1) Å] contacts present, and mol­ecules are also linked by C—H⋯O and π–π [centroid–centroid distance = 3.671 (2) Å] inter­actions

Comparison of the frequency and complications of inappropriate antidiuretic hormone secretion in patients with septic and aseptic meningitis

Objective Due to the high prevalence of syndrome of Inappropriate Antidiuretic Hormone Secretion (SIADH). This study was carried out to evaluate the prevalence and relevant parameters of SIADH in children with septic and aseptic memingitis hospitalized at Kashan Shahid Beheshti Hospital between 1996 and 2006. Materials & Methods This descriptive study was conducted on 230 patients with meningitis hospitalized in the pediatric wards of Kashan Shahid Beheshti Hospital between 1996 and 2006. Relevant information (age, gender, type of meningitis, serum sodium and potassium, urine specific gravity (USG), blood sugar, blood urea nitrogen, serum creatinin, hydration condition) was collected from patients' records. Datawas analyzed using Mann-Whitney and K2 tests. Results Out of 230 patients with meningitis, 33 had incomplete records and only 197 patients were recruited for this study. Sixty eight cases (34.5) suffered from SIADH. It was more frequent among 1-2 year old children. According to this research, SIADH was diagnosed in 57 of the 121 patients with hyponatremia, 58.7 of the 167 patients with USG > 1.004, 74 of the 93 patients with serum osmolity < 280 mOs/L and 100 of the patients with BUN < 10 mg. Conclusion Due to the high prevalence of SIADH in septic and aseptic meningitis and its complication, it is recommended to restrict fluid therapy and monitor serum sodium, urine specific gravity and other diagnostic tests for SIADH

Survival rate of patients with bladder cancer in Yazd, central province of Iran

Abstract Background: Bladder cancer is the ninth most commonly diagnosed malignancy worldwide. The trend of bladder cancer incidence and mortality is rising in Iran. This study was aimed to evaluate the survival rate of patients with bladder cancer in Yazd province, Iran. Methods: In this retrospective cohort study, data were collected from 340 patients suffering from bladder cancer referred to Shahid Rahnemon and Shohada-Kargar Hospitals in Yazd province, Iran between April, 2001 and March, 2012. Variables included age, gender, stage of cancer, place of residence and type of treatment. The Kaplan-Meier and Cox regression analyses were used to evaluate the relationship between each variable and survival time. A P value less than 0.05 was considered significant. Results: The mean age of total patients was 65.8 ± 13.6 years, and their mean survival time was 68.55 ± 6.05 months. Cumulative survival rates at the end of 1, 3, and 5 years in bladder cancer patients were 91%, 58%, and 51.4%, respectively. A statistically significant association was found between age (P = 0.005), stage of disease (P = 0.0003), type of treatment (P = 0.0003) and survival time of patients. Data showed no significant correlation between age, gender, place of residence and patients’ survival. Conclusions: The survival of patients suffering from bladder cancer in this study was less than other reports. Patients’age and cancer stage were the effective factors in survival time. Continuous screening of older people for cancer diagnosis in early stages is seemed to improve survival in patients. Keywords: Bladder; Cancer; Survival Rate; Ira

Space and social distancing in managing and preventing COVID-19 community spread: An overview.

The spread of COVID-19 at a large scale and at a rapid pace indicates the lack of social distancing measures at multiple levels. The individuals are not to be blamed, nor should we assume the early measures were ineffective or not implemented. It is all down to the multiplicity of transmission factors that made the situation more complicated than initially anticipated. Therefore, in facing the COVID-19 pandemic, this overview paper discusses the importance of space in social distancing measures. The methods used to investigate this study are literature review and case study. Many scholarly works have already provided us with evidence-based models that suggest the influential role of social distancing measures in preventing COVID-19 community spread. To further elaborate on this important topic, the aim here is to look at the role of space not only at the individual level but at larger scales of communities, cities, regions, etc. The analysis helps better management of cities during the pandemics such as COVID-19. By reflecting on some of the ongoing research on social distancing, the study concludes with the role of space at multiple scales and how it is central to the practice of social distancing. We need to be more reflective and responsive to achieve earlier control and containment of the disease and the outbreak at the macro level. [Abstract copyright: © 2023 Published by Elsevier Ltd.