<SUP>1</SUP>H and <SUP>19</SUP>F dynamic nuclear polarization studies at X-band: <SUP>19</SUP>F differential enhancements

X-band dynamic nuclear polarization (DNP) measurements on 1H and 19F nuclei in 1,4-bis(trifluoromethyl)benzene, 1,2,4-trifluorobenzene and 19F nuclei in octafluorotoluene are reported. The free radical used in all these cases is tri-t-butylphenoxyl. Chemically shifted fluorines have been resolved and clear differential 19F DNP trends have been established in these systems. Q-enhancement corrections to ultimate-ultimate enhancement values are discussed. Three theoretical models of the radical-solvent interaction involving, respectively, transfer of an electron spin, M.O. treatment of solvent-radical interaction at separations around the van der Waals distance, and exchange polarization of the solvent molecule are reported. The latter, treated as a closed-shell perturbation in the molecular orbital framework, leads to an sp&#963; polarizability parameter which reflects the present experimentally observed 19F DNP trends reasonably well. Apart from the present work, the only other experimental results on 19F differential DNP are those of Dwek et al. at Q-band and their results have also been satisfactorily interpreted in terms of our sp&#963; polarizability approach

DFT Study of Planar Boron Sheets: A New Template for Hydrogen Storage

We study the hydrogen storage properties of planar boron sheets and compare them to those of graphene. The binding of molecular hydrogen to the boron sheet (0.05 eV) is stronger than that to graphene. We find that dispersion of alkali metal (AM = Li, Na, and K) atoms onto the boron sheet markedly increases hydrogen binding energies and storage capacities. The unique structure of the boron sheet presents a template for creating a stable lattice of strongly bonded metal atoms with a large nearest neighbor distance. In contrast, AM atoms dispersed on graphene tend to cluster to form a bulk metal. In particular the boron-Li system is found to be a good candidate for hydrogen storage purposes. In the fully loaded case this compound can contain up to 10.7 wt. % molecular hydrogen with an average binding energy of 0.15 eV/H2.Comment: 19 pages, 7 figures, and 3 table

Evaluating the seasonal accumulation of Heat units as an agroclimatic indicator on Baby corn (Zea mays L.) under different sowing windows

Temperature determines the plant's growth and development, which decides the onset of different phenophasic stages of the Baby corn. This study aimed to evaluate the phenological behaviour and yield of Baby corn (Zea mays L.) influenced by sowing windows and heat units with the field investigations carried out during winter (January – April) and kharif  (June – September) 2022 at Eastern Block Farm of Tamil Nadu Agricultural University, Coimbatore. Growing Degree Days (GDD), Photo Thermal Units (PTU), Helio Thermal Units (HTU), Relative Temperature Disparity (RTD), Heat Unit Efficiency (HUE) and seasonal efficiency were calculated at different phenological stages. The results revealed that early attainment of phenophases was noticed during winter (62.5 days - January 21st to 27th April) than kharif (77.1 days – 15th June to 4th October). Among seasons, higher accumulation of GDD (1553) and PTU (19099) was observed during kharif 2022, whereas maximum accumulation of HTU (9923) and RTD (2146) was observed in winter 2022. Seasonal efficiency was higher during kharif (118) than during the winter season (81). The sowing windows significantly influenced the higher accumulation of heat units and yield attributes. Hence, higher yield (11922.7 kg ha-1) and HUE (7.3) were obtained during kharif than in winter 2022 (yield – 7849 kg ha-1 and HUE – 5.8). Weather parameters showed a negative correlation except RH-I, WS, SR and HUE during winter 2022 (R2=0.802) and RH-II, WS, RF, Daylength, HUE during kharif 2022, which had a positive correlation (R2=0.795). Baby corn is highly sensitive to increasing temperature. Hence, the study expresses the effect of varying ambient temperature on the duration between the phenological stages and yield.  

Physicochemical and Phytochemical Examination of Medicinal Plants Used in Indigenous System of Medicine

The present paper deals with the physicochemical and phytochemical examination of seventy-six medicinal plants belonging to thirty-six dicot and six monocot families. These are used in indigenous system of medicine as well as local inhabitants either as single drugs or in combination, for the cure of various ailments. In physicochemical study, the parameters such as moisture content, pH (1% aqueous), total ash, acid insoluble ash, water-soluble extractive and alcohol soluble extractive were carried out. The preliminary phytochemical study was done for the detection of secondary metabolites such as alkaloid, flavonoid, glycoside, phenol, saponin, resin, steroid and tannin. The preliminary phytochemical study revealed the presence of alkaloid and saponin in 68.4%; flavonoid in 44.7%; glycoside, phenol and steroid in 72.37%; resin in 60.5% and tannin in 71% of selected medicinal plants

A framework for Operational Security Metrics Development for industrial control environment

Security metrics are very crucial towards providing insights when measuring security states and susceptibilities in industrial operational environments. Obtaining practical security metrics depend on effective security metrics development approaches. To be effective, a security metrics development framework should be scope-definitive, objective-oriented, reliable, simple, adaptable, and repeatable (SORSAR). A framework for Operational Security Metrics Development (OSMD) for industry control environments is presented, which combines concepts and characteristics from existing approaches. It also adds the new characteristic of adaptability. The OSMD framework is broken down into three phases of: target definition, objective definition, and metrics synthesis. A case study scenario is used to demonstrate an instance of how to implement and apply the proposed framework to demonstrate its usability and workability. Expert elicitation has also be used to consolidate the validity of the proposed framework. Both validation approaches have helped to show that the proposed framework can help create effective and efficient ICS-centric security metrics taxonomy that can be used to evaluate capabilities or vulnerabilities. The understanding from this can help enhance security assurance within industrial operational environments

Laparoscopy in management of appendicitis in high-, middle-, and low-income countries: a multicenter, prospective, cohort study.

BACKGROUND: Appendicitis is the most common abdominal surgical emergency worldwide. Differences between high- and low-income settings in the availability of laparoscopic appendectomy, alternative management choices, and outcomes are poorly described. The aim was to identify variation in surgical management and outcomes of appendicitis within low-, middle-, and high-Human Development Index (HDI) countries worldwide. METHODS: This is a multicenter, international prospective cohort study. Consecutive sampling of patients undergoing emergency appendectomy over 6 months was conducted. Follow-up lasted 30 days. RESULTS: 4546 patients from 52 countries underwent appendectomy (2499 high-, 1540 middle-, and 507 low-HDI groups). Surgical site infection (SSI) rates were higher in low-HDI (OR 2.57, 95% CI 1.33-4.99, p = 0.005) but not middle-HDI countries (OR 1.38, 95% CI 0.76-2.52, p = 0.291), compared with high-HDI countries after adjustment. A laparoscopic approach was common in high-HDI countries (1693/2499, 67.7%), but infrequent in low-HDI (41/507, 8.1%) and middle-HDI (132/1540, 8.6%) groups. After accounting for case-mix, laparoscopy was still associated with fewer overall complications (OR 0.55, 95% CI 0.42-0.71, p < 0.001) and SSIs (OR 0.22, 95% CI 0.14-0.33, p < 0.001). In propensity-score matched groups within low-/middle-HDI countries, laparoscopy was still associated with fewer overall complications (OR 0.23 95% CI 0.11-0.44) and SSI (OR 0.21 95% CI 0.09-0.45). CONCLUSION: A laparoscopic approach is associated with better outcomes and availability appears to differ by country HDI. Despite the profound clinical, operational, and financial barriers to its widespread introduction, laparoscopy could significantly improve outcomes for patients in low-resource environments. TRIAL REGISTRATION: NCT02179112

Ab initio studies of structures and properties of small potassium clusters

We have studied the structure and properties of potassium clusters containing even number of atoms ranging from 2 to 20 at the ab initio level. The geometry optimization calculations are performed using all-electron density functional theory with gradient corrected exchange-correlation functional. Using these optimized geometries we investigate the evolution of binding energy, ionization potential, and static polarizability with the increasing size of the clusters. The polarizabilities are calculated by employing Moller-Plesset perturbation theory and time dependent density functional theory. The polarizabilities of dimer and tetramer are also calculated by employing large basis set coupled cluster theory with single and double excitations and perturbative triple excitations. The time dependent density functional theory calculations of polarizabilities are carried out with two different exchange-correlation potentials: (i) an asymptotically correct model potential and (ii) within the local density approximation. A systematic comparison with the other available theoretical and experimental data for various properties of small potassium clusters mentioned above has been performed. These comparisons reveal that both the binding energy and the ionization potential obtained with gradient corrected potential match quite well with the already published data. Similarly, the polarizabilities obtained with Moller-Plesset perturbation theory and with model potential are quite close to each other and also close to experimental data.Comment: 33 pages including 10 figure

How accurate is an LCD screen version of the Pelli–Robson test?

Purpose: To evaluate the accuracy and repeatability of a computer-generated Pelli–Robson test displayed on liquid crystal display (LCD) systems compared to a standard Pelli–Robson chart. Methods: Two different randomized crossover experiments were carried out for two different LCD systems for 32 subjects: 6 females and 10 males (40.5 ± 13.0 years) and 9 females and 7 males (27.8 ± 12.2 years), respectively, in the first and second experiment. Two repeated measurements were taken with the printed Pelli–Robson test and with the LCDs at 1 and 3 m. To test LCD reliability, measurements were repeated after 1 week. Results: In Experiment 1, contrast sensitivity (CS) measured with LCD1 resulted significantly higher than Pelli–Robson both at 1 and at 3 m of about 0.20 log 1/C in both eyes (p < 0.01). Bland–Altman plots showed a proportional bias for LCD1 measures. LCD1 measurements showed reasonable repeatability: ICC was 0.83 and 0.65 at 1 and 3 m, respectively. In Experiment 2, CS measured with LCD2 resulted significantly lower than Pelli–Robson both at 1 and at 3 m of about 0.10 log 1/C in both eyes (p < 0.01). Bland–Altman plots did not show any proportional bias for LCD2 measures. LCD2 measurements showed sufficient repeatability: ICC resulted 0.51 and 0.65 at 1 and 3 m, respectively. Conclusions: Computer-generated versions of Pelli–Robson test, displayed on LCD systems, do not provide accurate results compared to classic Pelli–Robson printed version. Clinicians should consider that Pelli–Robson computer-generated versions could be non-interchangeable to the printed version

Evaluation of lymph node numbers for adequate staging of Stage II and III colon cancer

<p>Abstract</p> <p>Background</p> <p>Although evaluation of at least 12 lymph nodes (LNs) is recommended as the minimum number of nodes required for accurate staging of colon cancer patients, there is disagreement on what constitutes an adequate identification of such LNs.</p> <p>Methods</p> <p>To evaluate the minimum number of LNs for adequate staging of Stage II and III colon cancer, 490 patients were categorized into groups based on 1-6, 7-11, 12-19, and ≥ 20 LNs collected.</p> <p>Results</p> <p>For patients with Stage II or III disease, examination of 12 LNs was not significantly associated with recurrence or mortality. For Stage II (HR = 0.33; 95% CI, 0.12-0.91), but not for Stage III patients (HR = 1.59; 95% CI, 0.54-4.64), examination of ≥20 LNs was associated with a reduced risk of recurrence within 2 years. However, examination of ≥20 LNs had a 55% (Stage II, HR = 0.45; 95% CI, 0.23-0.87) and a 31% (Stage III, HR = 0.69; 95% CI, 0.38-1.26) decreased risk of mortality, respectively. For each six additional LNs examined from Stage III patients, there was a 19% increased probability of finding a positive LN (parameter estimate = 0.18510, p < 0.0001). For Stage II and III colon cancers, there was improved survival and a decreased risk of recurrence with an increased number of LNs examined, regardless of the cutoff-points. Examination of ≥7 or ≥12 LNs had similar outcomes, but there were significant outcome benefits at the ≥20 cutoff-point only for Stage II patients. For Stage III patients, examination of 6 additional LNs detected one additional positive LN.</p> <p>Conclusions</p> <p>Thus, the 12 LN cut-off point cannot be supported as requisite in determining adequate staging of colon cancer based on current data. However, a minimum of 6 LNs should be examined for adequate staging of Stage II and III colon cancer patients.</p