Molecular dynamics calculations of collision-induced absorption in a gas mixture of neon and krypton.

We continue the development of the in-house molecular dynamics software package SpaCIAL and test it for the computation of the collision-induced absorption coefficients for a neon (Ne) and krypton (Kr) gas mixture. An apodization procedure for the dipole autocorrelation function is implemented and tested. We also carry out a statistical study of the convergence rate with respect to ensemble size. The resulting absorption coefficients show a good accordance with quantum mechanical results. Comparison with laboratory measurements shows agreement within 10%-20% at T = 295 K. At T = 480 K, a larger difference of 40%-80% is observed, which can presumably be explained by experimental uncertainties. For the study, an empirical (Barker, Fisher, and Watts) interaction-potential [Mol. Phys. 21, 657 (1971)] for Ne-Kr has been developed. Ab initio {coupled cluster with singles and doubles (triples) [CCSD(T)]} potentials for Ne-Ne, Kr-Kr, and Ne-Kr have been computed, as well as the CCSD(T) interaction-induced Ne-Kr dipole moment curve.

Collision-induced absorption in Ar-Kr gas mixtures: A molecular dynamics study with new potential and dipole data.

We have implemented a scheme for classical molecular dynamics simulations of collision-induced absorption. The program has been applied to a gas mixture of argon (Ar) and krypton (Kr). The simulations are compared with accurate quantum dynamical calculations. The comparisons of the absorption coefficients show that classical molecular dynamics is correct within 10% for photon wave numbers up to 220 cm-1 at a temperature of 200 K for this system. At higher temperatures, the agreement is even better. Molecular dynamics accounts for many-body interactions, which, for example, give rise to continuous dimer formation and destruction in the gas. In this way, the method has an advantage compared with bimolecular classical (trajectory) treatments. The calculations are carried out with a new empirical Ar-Kr pair potential. This has been obtained through extensive analysis of experimental thermophysical and transport properties. We also present a new high level ab initio Ar-Kr potential curve for comparison, as well as ab initio interaction-induced dipole curves computed with different methods. In addition, the Ar-Kr polarizability and hyperpolarizability are reported. A comparison of the computed absorption spectra with an experiment taken at 300 K shows satisfactory agreement although a difference in absolute magnitude of 10%-15% persists. This discrepancy we attribute mainly to experimental uncertainty.

Exceptional Multiple Foreign-Body Ingestion by a Patient with Schizophrenia.

Swallowing foreign body in adult is uncommon. This mostly occurs accidentally or in psychologically unsound patient. A 32-years-old male patient with abdominal pain admitted in surgery department of Mymensingh Medical College Hospital, Mymensingh, Bangladesh with a history of swallowing various objects. After endoscopic confirmation and psychological evaluation he underwent laparotomy and 29 different objects were removed from his stomach by Gastrotomy. He was psychiatrically evaluated after recovery from operation and was found to be suffering from Schizophrenia with cannabis use. The aim of reporting this case can raise awareness at the patients complains should be taken seriously to prevent morbidity and even mortality.

Early Outcome of Primary Repair in Colonic Injury.

The management of the colon injury remains controversial in spite of a number of divergent reports during the past decade. Previously surgeons were reluctant to do primary anastomosis but now-a-days they are doing primary repair with good results. The present study is designed to see the early outcomes of primary repair in colonic injury. This prospective observational study performed at Dhaka Medical College Hospital, Dhaka, Bangladesh from January 2013 to June 2013 with allocation of 50 patients with colonic injury who underwent laparotomy with primary repair of that injury in the department of Casualty Surgery. A primary repair was performed after freshening the edges or by resection and primary anastomosis with 3.0 round-body Vicryl by single layer extra mucosal interrupted suture. Data processed using software SPSS version 16.0. For all analytical results a p value <0.05 was considered significant. In this study the commonest site of injury were transvers colon and sigmoid colon 38.0% in each. Out of 50 respondents, 5(10.0%) developed burst abdomen, 1(2.0%) developed entero-cutaneous fistula with none had paralytic ileus or septicaemia or pelvic collection. No mortality observed. This study showed that the increasing in colon injury scale (CIS) score culminate into increasing rate of postoperative complication & post operative complications were more at left colon (24%). On basis of our findings, we recommend the primary repair is a safe and effective surgical technique for addressing the large gut injury. Unnecessary proximal diversions should be avoided. According to our experience, we believe that the policy of primary repair of colon injuries can be applied more liberally in majority of patients with high success rate.

Contributions of multipolar polarizabilities to the isotropic and anisotropic light scattering induced by molecular interactions in gaseous methane.

The binary isotropic and anisotropic collision-induced light scattering spectra of gaseous methane at room temperature are analyzed in terms of a recent ab initio intermolecular potential and interaction-induced pair polarizability trace and anisotropy models, using quantum line-shapes computations. The translational spectra at relatively low frequencies are determined largely by the effects of bound and free transitions. At intermediate frequencies the spectra are sensitive to both the attractive part of the potential and the short-range part of the polarizability trace and anisotropy. The high frequency wings are discussed in terms of the collision-induced rotational Raman effect and estimates for the dipole-quadrupole polarizability A and the dipole-octopole polarizability E are obtained and checked with recent ab initio theoretical values.

Extracorporeal shock wave lithotripsy (ESWL) monotherapy in children: Predictors of successful outcome.

INTRODUCTION AND OBJECTIVES: Although extracorporeal shock wave lithotripsy (ESWL) is the first choice for pediatric renal calculi <2 cm, the success rate after the first session is low. This is in contrast to other minimally invasive procedures like percutanous nephrolithotomy (PCNL) and retrograde intrarenal surgery (RIRS), which have higher rates of success. Therefore, the present study sought to identify predictors of success after one session of ESWL. PATIENTS AND METHODS: A prospective study including 100 children with renal stone burden <2 cm who underwent ESWL at the present institution. The success rate after the first session was analyzed, and the predictors of success were investigated. The success of ESWL monotherapy was defined by absence of any residual fragments after 3 months, on non-contrast spiral computerized tomography (NCCT) scan, without need of any additional intervention. RESULTS: Between January 2013 and October 2015, 100 children were treated with a Dornier Gemini lithotripter at the present institution. The mean patients age and stone size were 6 years (range: 1.8-14) and 13.1 mm (range: 6-20), respectively. After one session, 47% of patients showed complete clearance 3 months postoperative, those patients versus those who required an additional session or auxiliary procedures were younger in age, with smaller stone size and lower density. On multivariate analysis, only patient age was an independent predictor of success (odds ratio (OR) 0.9; P < 0.001). CONCLUSION: Patient's age was an important predictor for response after ESWL monotherapy: not only did children respond better than adults, but age was also an independent predictor within the pediatric group.

Antimicrobial isoflavans from Astragalus species.

Two new antimicrobial isoflavans, 1-[(3R)-7,8-dimethoxybenzopyranyl]-4- hydroxybenzoquinone (astragaluquinone) and (3S)-7,1'-dihydroxy-8,3'-dimethoxyisoflavan (8-methoxyvestitol), and the known 7-hydroxy-2',3',4'-trimethoxyisoflavan were isolated from roots of Astragalus alexandrinus and A. trigonus. The structures of the new isoflavans were established by spectroscopic methods.

Laparoscopic versus open orchiopexy in the management of peeping testis: a multi-institutional prospective randomized study.

OBJECTIVE: Peeping testis is an inconsistently palpable/seen undescended testis that migrates back and forth at the internal inguinal ring. Both open and laparoscopic orchiopexy are effective forms of management. The present study aimed to evaluate the efficacy and safety of both approaches. PATIENTS AND METHODS: Between September 2007 and January 2012, 46 peeping inguinal testes were randomly treated with either open (25 cases) or laparoscopic (21 cases) orchiopexy procedures. Spermatic vessels were preserved for all cases. Operative details, postoperative morbidity and final testicular site and size were recorded. RESULTS: The median age of the children was 2.5 years (range 0.5-12.0). The follow-up period ranged from 1.0 to 5.5 years. Of these testes, 20 in the open surgery group and 19 in the laparoscopic group maintained correct intrascrotal position (P = 0.428). Re-do orchiopexy was indicated for two cases in the surgical group (P = 0.493). No cases of testicular atrophy or hernia were encountered. CONCLUSION: Open and laparoscopic orchiopexy procedures for peeping testes are fairly comparable. However, laparoscopy is relatively more effective, as two re-do orchiopexies were required in the open surgical group.

Multiproperty empirical isotropic interatomic potentials for CH4-inert gas mixtures.

An approximate empirical isotropic interatomic potentials for CH4-inert gas mixtures are developed by simultaneously fitting the Exponential-Spline-Morse-Spline-van der Waals (ESMSV) potential form to viscosity, thermal conductivity, thermal diffusion factors, diffusion coefficient, interaction second pressure virial coefficient and scattering cross-section data. Quantum mechanical lineshapes of collision-induced absorption (CIA) at different temperatures for CH4-He and at T = 87 K for CH4-Ar are computed using theoretical values for overlap, octopole and hexadecapole mechanisms and interaction potential as input. Also, the quantum mechanical lineshapes of collision-induced light scattering (CILS) for the mixtures CH4-Ar and CH4-Xe at room temperature are calculated. The spectra of scattering consist essentially of an intense, purely translational component which includes scattering due to free pairs and bound dimers, and the other is due to the induced rotational scattering. These spectra have been interpreted by means of pair-polarizability terms, which arise from a long-range dipole-induced-dipole (DID) with small dispersion corrections and a short-range interaction mechanism involving higher-order dipole-quadrupole A and dipole-octopole E multipole polarizabilities. Good agreement between computed and experimental lineshapes of both absorption and scattering is obtained when the models of potential, interaction-induced dipole and polarizability components are used.

Impact of weight loss on markers of systemic inflammation in obese Saudi children with asthma.

BACKGROUND: Weight loss studies were conducted in children without asthma have demonstrated a reduction in systemic inflammation. However, the impact of weight loss in the obese paediatric population with asthma has not been investigated. OBJECTIVE: To measure the effects of weight loss on markers of systemic inflammation in obese children with bronchial asthma. METHODS: Eighty obese children with bronchial asthma (42 boys, and 38 girls) with mean age 13.86 ± 3.21 years were divided into two equal groups. The training group received diet regimen, exercise training in addition to the medical treatment for two months, where the control group received the medical treatment only. RESULTS: There was a 17.5%, 15.5%, 22.4%, 14.1% and 15.9% reduction in mean values of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), interleukin-8 (IL-8), Leptin and body mass index (BMI) respectively and 38.7 % increase in mean values of adiponectin in the training group. While, there was a 0.7%, 9.0%, 2.8%, 1.6% and 1.2% increase in mean values of TNF-alpha, IL-6, IL-8, Leptin and BMI respectively and 3.9% decrease in mean values of adiponectin in the control group. The mean values of TNF-alpha, IL-6, IL-8, Leptin and BMI was decreased and adiponectin was increased significantly in the training group, however the results of the control group were not significant. Also, there were significant differences between both groups at the end of the study. CONCLUSION: Weight loss improves markers of systemic inflammation in obese Saudi children with bronchial asthma.

Reconstruction of long anterior urethral strictures by dorsally quilted penile skin flap.

Objective. To present the results of reconstruction of long (>5 cm), penile, bulbar, and bulbopenile urethral strictures by penile skin flap as dorsal onlay in one-stage procedure. Patients and Methods. Between January, 1998 and December, 2004, 18 patients (aged from 28-65 years) presented with long urethral strictures, 5.6-13.2 cm (penile in 6, bulbar in 2 and combined in 10 cases), those were repaired utilizing long penile skin flaps placed as dorsal onlay flap in one stage (Orandi flap 6 cm in 6 cases, circular flaps 7-10 cm in 8, and spiral flaps 10-15 cm in 4). Followup of all patients after reconstruction included urine flow rate at weekly intervals, RUG at 6-12 weeks, and urethrocystoscopy at 12 and 18 months. Results. The urethral patency was achieved in 77% of patients. The complications were fistula in one patient (5.5%), restricture occurred in 3 patients (16.6%) that required visual internal urethrotomy and two patients (11%) showed curvature on erection that dose not interfere with sexual intercourse. Diverticulum (penile urethra) was seen in one patient (5.5%) containing stones and was excised surgically. There was penile skin loss in 3 patients (16.6%). All patients completed at least one-year followup period. Conclusion. Free penile skin flaps offer good results (functional and cosmetic) in long penile and/or bulbar urethral strictures. Meticulously fashioned longitudinal, circular or spiral penile skin flaps could bridge urethral defects up to 15 cm long.

HPTLC densitometric analysis of arbutin in bulk drug and methanolic extracts of Arctostaphylos uva-ursi.

A high-performance thin layer chromatographic densitometric method for the analysis of arbutin was developed and validated in the present investigation. Arbutin was separated on aluminium-backed silica gel 60 F(254) plates with methanol : chloroform (3:7)% (v/v) as the mobile phase. This system was found to give a compact spot of arbutin at a retention factor (R(f)) value of 0.32 ± 0.02. The limit of detection and limit of quantification were found to be 35.42 and 106.26 ng/spot, respectively. The proposed method with a high degree of precision and accuracy was employed for the analysis of arbutin in the bulk drug and methanolic extract of Arctostaphylos uva-ursi.

Phenolic constituents of Ononis vaginalis roots.

The ether soluble fraction of the roots of Ononis vaginalis Vahl. Symb. afforded three new compounds: 3-hydroxy-4,9-dimethoxycoumestan, maginaldehyde [2-(4-hydroxy-2-methoxyphenyl)-5,6-dimethoxy-3-benzofuran-carboxaldehyde] and 5,7,4'-trihydroxy-4-styrylcoumarin. In addition, four known pterocarpans; 3,4,9-trimethoxypterocarpan, maackiain, medicarpin and trifolirhizin were also isolated. The styrylcoumarin derivative showed significant antiviral activity against Herpes simplex type 1 and weak cytotoxicity.

Erythroxan diterpenes from Fagonia glutinosa.

Further investigation of the ether extract of the aerial parts of Fagonia glutinosa utilizing the brine shrimp bioassay resulted in the isolation of two new cytotoxic erythroxan diterpenes: 1 alpha, 10 alpha-epoxy-2-oxofagonene (1) and 1 beta, 10 beta-epoxy-2-oxofagonene (2). In addition, two inactive diterpenes, 2-oxofagonene (3) and its previously reported isomer 2-oxo-5-epi-fagonene (4), were also isolated.

Lanigerol: a new antimicrobial icetexane diterpene from Salvia lanigera.

Roots of Salvia lanigera Poir. yielded a new icetexane [10,12-dihydroxy-9(10-->20)-abeo-8,11,13-abietatriene], named lanigerol, which had activity (MIC 1 mg/ml) against Gram-positive bacteria.

Bioactive iridoids and a new lignan from Allamanda cathartica and Himatanthus fallax from the Suriname rainforest.

Bioassay-guided fractionation of the EtOAc extract of both Allamanda cathartica and Himatanthus fallax (Apocynaceae) using the Sc-7 yeast strain resulted in the isolation of the weakly cytotoxic isoplumericin and plumericin. In addition, the new lignan 7(R)-methoxy-8-epi-matairesional and three known compounds, plumieride, matairesinol, and pinoresinol, were isolated from H. fallax.

Bioactive saponins from Swartzia schomburgkii from the suriname rainforest.

Bioassay-guided fractionation of the MeOH extract of Swartzia schomburgkii using the engineered yeast strains 1138, 1140, and 1353 as the bioassay tool resulted in the isolation of five active (2, 4-7) and three inactive (1, 3, 8) saponins. Saponins 4 and 6 are previously unreported. The structures of all of the saponins were established based on 1D and 2D NMR spectral analysis, on acid and alkaline hydrolysis followed by TLC and GC-MS, and by comparison with literature data for known compounds. Three of the isolated compounds (4-6) showed weak cytotoxicity against the M-109 cell line.

DNA-damaging steroidal alkaloids from Eclipta alba from the suriname rainforest1.

Bioassay-guided fractionation of the MeOH extract of Eclipta alba using three yeast strains (1138, 1140, and 1353) resulted in the isolation of eight bioactive steroidal alkaloids (1-8), six of which are reported for the first time from nature. The major alkaloid was identified as (20S)(25S)-22,26-imino-cholesta-5,22(N)-dien-3beta-ol (verazine, 3), while the new alkaloids were identified as 20-epi-3-dehydroxy-3-oxo-5,6-dihydro-4,5-dehydroverazine (1), ecliptalbine [(20R)-20-pyridyl-cholesta-5-ene-3beta,23-diol] (4), (20R)-4beta-hydroxyverazine (5), 4beta-hydroxyverazine (6), (20R)-25beta-hydroxyverazine (7), and 25beta-hydroxyverazine (8). Ecliptalbine (4), in which the 22,26-imino ring of verazine was replaced by a 3-hydroxypyridine moiety, had comparable bioactivity to verazine in these assays, while a second alkaloid (8) showed good activity against Candida albicans. All the alkaloids showed weak cytotoxicity against the M-109 cell line.