157 research outputs found
More on Comparison Between First Geometric-Arithmetic Index and Atom-Bond Connectivity Index
The first geometric-arithmetic (GA) index and atom-bond connectivity (ABC)
index are molecular structure descriptors which play a significant role in
quantitative structure-property relationship (QSPR) and quantitative
structure-activity relationship (QSAR) studies. Das and Trinajsti\'{c}
[\textit{Chem. Phys. Lett.} \textbf{497} (2010) 149-151] showed that index
is greater than index for all those graphs (except and ,
see Figure 1) in which the difference between maximum and minimum degree is
less than or equal to 3. In this note, it is proved that index is greater
than index for line graphs of molecular graphs, for general graphs in
which the difference between maximum and minimum degree is less than or equal
to (where is the minimum degree and )
and for some families of trees. Thereby, a partial solution to an open problem
proposed by Das and Trinajsti\'{c} is given.Comment: 10 pages, 2 tables, 1 figure, revised versio
A Monte Carlo Simulation Analysis of Panel Stationarity Tests under a Single Framework
A unified framework, stringency criterion have been used to compare the six panel unit root tests having the null hypothesis of stationary and to find the best performer test/tests. Simulated critical values, instead of asymptotic critical values, have been used to keep the size of all tests around nominal size of 5%. Our findings suggest HD and HL tests as better performing tests as compared to other panel stationarity tests
Detonations in H_2-N_2O-CH_4-NH_3-O_2-N_2 Mixtures
This report describes experimental studies and analyses on the detonation properties of flammable
gases that may be present in the waste storage tanks at Hanford, WA. These studies were carried
out in the Explosion Dynamics Laboratory, part of the the Graduate Aeronautical Laboratories of
the California Institute of Technology (GALCIT). Detonation cell sizes and pressures were measured
in the GALCIT detonation tube facility for mixtures of hydrogen, ammonia, methane, nitrous oxide,
oxygen and nitrogen. Measurements were made as a function of nitrogen and air dilution for
stoichiometric mixtures of fuels and oxidizers and also specific retained gas compositions of tanks
such as SY-101. Chemical kinetic modeling of these mixtures has been performed using the idealized
ZND model. Existing reaction mechanisms and rate constant sets were benchmarked against shock
tube data available in the literature. Correlations between reaction zone length and detonation cell
width were developed that can be used to correlate and extrapolate the existing experimental data
base
Functional Parathyroid Cyst: A Rare Cause of Malignant Hypercalcemia with Primary Hyperparathyroidism—A Case Report and Review of the Literature
Parathyroid cysts are rare lesions found in the neck and anterior mediastinum. They are often nonfunctional (>90%) and rarely in the functional form. This paper discusses a case of severe hypercalcemia (23 mg/dL) secondary to a rare functional parathyroid cyst. The patient was later found to have a hemorrhagic cyst with compression of the right recurrent laryngeal nerve. Preoperative diagnosis of the lesion was parathyroid carcinoma. However, reexploration of the parathyroid mass along with microscopic study confirmed the diagnosis of a parathyroid cyst. Following cystectomy, the patient restored her baseline functional status with preservation of the right recurrent laryngeal nerve. Postoperative followup three years later showed no evidence of cyst recurrence. This paper illustrates the rare presentation of parathyroid functional cysts with severe hypercalcemia and primary hyperparathyroidism. Physicians should be aware of the presence of hemorrhage, inflammation, and compressive symptoms in these cysts which mimic parathyroid carcinoma. These patients should be managed with aggressive medical and surgical intervention
Manifestation of Mobile Phone Assisted Personal Agency among University Students: Evidence from Lahore
The study was carried out to explore the manifestation of mobile phone assisted personal agency among university students. Personal Agency of Mobile Phone Users Scale was adapted to measure the practice of personal agency. The questionnaire was administered to a sample of 401 university students in Lahore. Findings of the study indicated three constituents of personal agency among youth; contactability, organizability and derestriction. Furthermore, duration of the possession of mobile phone was found significantly correlated with the practice of mobile phone assisted personal agency. Respondents reported that mobile phone has conferred upon them a sense of individual freedom and social connectedness. It has helped them to organize their daily activities. According to them, this electronic gadget has enabling effect and it enlivened their lives through its beeps and bells. The findings of the study are aligned with the results of D’Souza (2010) who did the pioneering study in exploring personal agency through mobile phone use. However, further research is required to explore the impact of mobile phone use on the lives of youth who have not been enrolled in the universities. 
Vitamin D deficiency (VDD) and susceptibility towards severe Dengue fever:a prospective cross-sectional study of hospitalized Dengue fever patients from Lahore, Pakistan
Dengue is a mosquito-borne flaviviral serious febrile illness, most common in the tropical and subtropical regions including Pakistan. Vitamin D is a strong immunomodulator affecting both the innate and adaptive immune responses and plays a pivotal role in pathogen-defense mechanisms. There has been considerable interest in the possible role of vitamin D in dengue viral (DENV) infection. In the present prospective cross-sectional study, we assessed a possible association between serum vitamin D deficiency (VDD) and susceptibility towards severe dengue fever (DF) illness. Serum vitamin D levels were measured at the time of hospitalization in 97 patients diagnosed with dengue fever (DF), dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS) at Mayo Hospital, King Edward Medical University, Lahore, PK, from 16 November 2021 to 15 January 2022. In terms of disease severity, 37 (38.1%) patients were DF, 52 (53.6%) were DHF grade 1 and 2, and 8 (8.2%) were DSS. The results revealed that most patients (75 (77.3%)) were vitamin-D-deficient (i.e., serum level < 20 ng/mL), including 27 (73.0%) in DF, 41 (78.8%) in DHF grade 1 and 2, and 7 (87.5%) in DSS. The degree of VDD was somewhat higher in DSS patients as compared to DF and DHF grade 1 and 2 patients. Overall, serum vitamin D levels ranged from 4.2 to 109.7 ng/mL, and the median (IQR) was in the VDD range, i.e., 12.2 (9.1, 17.8) ng/mL. Our results suggest that there may be a possible association between VDD and susceptibility towards severe dengue illness. Hence, maintaining sufficient vitamin D levels in the body either through diet or supplementation may help provide adequate immune protection against severe dengue fever illness. Further research is warranted.</p
Synthesis, Spectroscopic Characterization, DFT and Molecular Dynamics of Quinoline-based Peptoids
Peptoids mimic the functions of peptides which have a side chain appended to amidic nitrogen instead of α carbon. This structural change in their backbone gives them increased resistance from proteolysis, improved biostability, greater immunogenicity, and better bioavailability. Therefore, they are specifically designed for various biological activities, including antibacterial, antifungal, antioxidant, antifouling, and anticancer properties. The aim of the research is the one-pot synthesis of quinoline-based peptoids 5(a-b) via Ugi-4CR by the reaction of 1R-(-)-myrtenal 1, benzylamine 2, quinoline-based carboxylic acids 3(a-b), and cyclohexyl isocyanide 4. These peptoids were characterized by FT-IR, 1H NMR, 13C NMR, and HR ESI-MS. In computational studies, the spectral results of 5(a-b) were compared with the calculated spectral values computed at B3LYP/6-311G (d,p) level. TD-DFT method was used to predict electron excitation of 5(a-b) and the contribution of orbitals. The electronic transition of peptoids from charge distribution was computed using natural bond order (NBO) analysis. NPA and MEP analysis was calculated to predict charge distribution in 5(a-b). The FMOs analysis was executed to calculate the global reactivity descriptor to predict the reactivity and stability of peptoids. DFT analysis showed that 5b was slightly more reactive than 5a due to extended conjugation. The biological activities were also predicted using an in silico approach that involved molecular docking and molecular dynamic (MD) simulations. The antiulcer, antibacterial, and antifungal activities were predicted based on ligand–protein binding interactions, binding energy calculations, and dissociation constants. 5(a-b) were evaluated in-vitro for anticholinesterase activity, and they showed 71% inhibition. The umbrella sampling was performed to probe ligand–protein binding
Marginal Trade-Offs for Improved Agro-Ecological Efficiency Using Data Envelopment Analysis
Today’s agricultural management decisions impact food security and sustainable ecosystems, even when operating with back-to-basic operations. In such endeavors, policymakers usually need a quantitative tool, such as trade-offs margins, to effectively adjust resource consumption or production. This paper applies the weighted slack-based measurement (SBM-DEA) program to 136 developing countries’ agricultural performance. First, it finds the current agricultural efficiency and then makes marginal trade-offs on desirable-output variables (such as crop yield and forest area) to see the effective changes in undesirable-output (such as methane and nitrous oxide emissions). The results show that choosing effective marginal trade-offs does not deteriorate the relative efficiency of the decision-making units (DMUs) below the efficient frontier line. Thus, such a method enables the decision-makers to determine the best marginal trade-off points to reach the optimal efficiencies and decide which output factor needs special brainstorming to design effective policy
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