Density functional theory study of the structure, stability, magnetic properties, and (hyper)polarizability of (sub-nm) rare-earth (RE) doped gold clusters: Au5RE with RE = Sc, Y, La-Lu

Rare-earth doped materials are of immense interest for their potential applications in linear and nonlinear photonics. There is also intense interest in sub-nanometer gold clusters due to their enhanced stability and unique optical, magnetic, and catalytic properties. To leverage their emergent properties, here we report a systematic study of the geometries, stability, electronic, magnetic, and linear and nonlinear optical properties of Au5RE (RE = Sc, Y, La-Lu) clusters using density-functional theory. Several low-energy isomers consisting of planar or non-planar configurations are identified. For most doped clusters, the non-planar configuration is energetically favored. In the case of La-, Pm-, Gd-, and Ho-doped clusters, a competition between planar and non-planar isomers is predicted. A distinct preference for the planar configuration is predicted for Au5Eu, Au5Sm, Au5Tb, Au5Tm, and Au5Yb. The distinction between the planar and non-planar configurations is highlighted by the calculated highest frequencies, with the stretching mode of the non-planar configuration predicted to be stiffer than the planar configuration. The bonding analysis reveals the dominance of the RE-d orbitals in the formation of frontier molecular orbitals, which, in turn, facilitates retaining the magnetic characteristics governed by RE-f orbitals, preventing spin-quenching of rare earths in the doped clusters. In addition, the doped clusters exhibit small energy gaps between frontier orbitals, large dipole moments, and enhanced hyperpolarizability compared to the host cluster.

AIH in HIV: A Very Much Possible Entity

Autoimmune Hepatitis (AIH) is a chronic liver disease Characterized by interface hepatitis, lymphoplasmacytic infiltrate, and hepatic rosettes. HIV infection is a state of immunosuppression; hence, the possibility of AIH is relatively rare, especially in patients with low CD4 counts. Therefore, we present an interesting case series of four patients with autoimmune liver disease with myriad presentations for the first time from India. We propose that despite the rarity of this presentation with immunosuppression, one should never miss such a treatable cause of liver disease leading to good clinical outcomes.

Can the Pirani Score Predict the Number of Casts and the Need for Tenotomy in the Management of Clubfoot by the Ponseti Method?

Introduction: We assessed the role of the Pirani score in determining the number of casts and its ability to suggest requirement for tenotomy in the management of clubfoot by the Ponseti method.

Materials and Methods: Prospective analysis of 66 (110 feet) cases of idiopathic clubfoot up to one year of age was done. Exclusion criteria included children more than one year of age at the start of treatment, non-idiopathic cases and previously treated or operated cases.

Results: The initial Pirani score was (5.5±0.7) for the tenotomy group and the initial Pirani score was (3.3±1.6) for the non-tenotomy group. There was a significant difference between the initial Pirani score for the tenotomy and the non-tenotomy group with t= -7.9, df= 64 p<0.0001. The tenotomy group had a significantly higher number of casts (four to seven) compared to non-tenotomy group (two to five) t=-10.4, df=64, p<0.0001. Spearman’s rank correlation coefficient was significant and confirmed positive correlation between the initial Pirani score and the number of casts required to correct the deformity (r = 0.931, p<0.0001).

Conclusion: Initial high Pirani score suggests the need for greater number of casts to achieve correction and probable need for tenotomy. The number of casts required in achieving complete correction increases with increase in the initial Pirani score. The initial high hindfoot score (2.5-3) signifies the probable need of a minor surgical intervention of percutaneous tendoachilles tenotomy. Based on the initial Pirani score, parents can be informed about the probable duration of treatment and the need for tenotomy.

Hesperidin promotes programmed cell death by downregulation of nongenomic estrogen receptor signalling pathway in endometrial cancer cells

Endometrial carcinoma (EC) is the most common malignant gynecologic tumor in women. EC is thought to be caused by increasing estrogen levels relative to progesterone in the body. Hesperidin (Hsd), a biologically active flavonoid, could be extracted from Citrus species. It has been recently shown that Hsd could exert anticarcinogenic properties in different cancer types. However, the effects of Hsd and its molecular mechanisms on EC remain unclear. In this study, the antiproliferative, apoptotic and genomic effects of Hsd in EC and its underlying mechanisms were identified. We found that Hsd significantly suppressed the proliferation of EC cells in dose and time dependent manner. Mechanistic studies showed that Hsd could contribute apoptosis by inducing externalization of phosphatidyl serine (PS), caspase-3 activity and loss of mitochondrial membrane (MMP). Furthermore, we examined that Hsd could also significantly upregulate the expression of proapoptotic Bax subgroup genes (Bax and Bik) while downregulating the anti-apoptotic protein Bcl-2 in EC cell lines. According to GO enrichment and KEGG pathway analysis of differentially expressed genes in Hsd treated EC cells, we identified that Hsd could promote cell death via downregulation of estrogen receptor I (ESRI) that was directly related to ERK/MAPK pathway. Taken together, our study first showed that Hsd could be an antiestrogenic compound that could modulate nongenomic estrogen receptor signaling through inhibition of EC cell growth. Our findings may provide us a novel growth inhibitory agent for EC treatment after verifying its molecular mechanism with in vivo studies.

Overexpression of SbAP37 in rice alleviates concurrent imposition of combination stresses and modulates different sets of leaf protein profiles

SbAP37 transcription factor contributes to a combination of abiotic stresses when applied simultaneously in rice. It modulates a plethora of proteins that might regulate the downstream pathways to impart salt stress tolerance. APETALA type of transcription factor was isolated from Sorghum bicolor (SbAP37), overexpressed in rice using a salt inducible abscisic acid 2 (ABA2) promoter through Agrobacterium tumefaciens following in planta method. Transgenics were confirmed by PCR amplification of SbAP37, hygromycin phosphotransferase (hptII) marker and ABA2 promoter and DNA blot analysis. Plants were exposed to 150 mM NaCl coupled with high day/night 36 ± 2/25 ± 2 °C temperatures and also drought stress by withholding water for 1-week separately at the booting stage. SbAP37 expression was 2.8- to 4.7-folds higher in transgenic leaf under salt, but 1.8- to 3.3-folds higher in roots under drought stress. Native gene expression analysis showed that it is expressed more in stem than in roots and leaves under 150 mM NaCl and 6% PEG stress. In the present study, proteomic analysis of transgenics exposed to 150 mM NaCl coupled with elevated temperatures was taken up using quadrupole time-of-flight (Q-TOF) mass spectrometry (MS). The leaf proteome revealed 11 down regulated, 26 upregulated, 101 common (shared), 193 newly synthesized proteins in transgenics besides 368 proteins in untransformed plants. Some of these protein sets appeared different and unique to combined stresses. Our results suggest that the SbAP37 has the potential to improve combined stress tolerance without causing undesirable phenotypic characters when used under the influence of ABA2 promoter.

Case of Phthiriasis palpebrarum with blepheroconjunctivitis

A 70-year-old woman came to ophthalmology outpatient department with complaints of repeated episodes of itching, redness and watering in both eyes of 3 months duration. She was treated with antibiotics elsewhere but had no improvement. Slit lamp examination showed lice and nits anchored to the eyelashes. Light microscopic examination of the matted eye lashes and crusts further helped in identification of the ectoparasites as Phthirus pubis (Pubic louse or Crab louse) with typical morphology.

Neonatal umbilical myiasis with sepsis

The authors report a 9-day old neonate from a rural area with umbilical myiasis caused by fly larvae of Cochliomyia hominivorax. The blowfly causing this infestation belongs to the family Calliphoridae (Diptera) and the genus Cochliomyia that usually infests only open wounds of animals. The new-world screw-worm fly Cochliomyia hominivorax, is an obligate ectoparasite of domestic and wild animals, and in some cases may affect humans. This is the rare reported case of neonatal umbilical myiasis with sepsis in the world literature.

Pseudoaneurysm of brachiocephalic artery caused by blunt chest trauma

Traumatic aneurysms of the brachiocephalic artery may cause mostly nonspecific symptoms, which may lead to a misdiagnosis with serious complications. This report describes a 27-year-old woman with a traumatic aneurysm of the brachiocephalic artery,suffering from lung symptoms. Brachiocephalic aneurysm and bronchiectasis were diagnosed by chest CT scan. A bypass from the ascending aorta to the distal brachiocephalic artery with a prosthetic graft and aneurysmectomy were performed without the use of cardiopulmonary bypass. The patient had an uneventful recovery.

Effect of acute maximal exercise on lymphocyte subgroups in type 1 diabetes

The essential therapy of diabetes mellitus includes medical nutrition therapy (MNT), exercise and medical therapy. Exercise, besides its metabolic effects, has positive influence on the immune system, but some forms of exercise may cause trauma for muscle and skeletal systems, they may also support negative effects on the immune system. Nineteen type 1 diabetic patients (mean age 22.1 +/- 2.8 yrs), followed by Diabetes Outpatient Clinic and twenty age matched male control subjects were included into the study, to demonstrate the effects of maximal, acute exercise on the immune system. The exercise test was performed according to Bruce protocol on treadmill. In diabetic subjects, increased CD19 and CD23 expressions were observed before exercise. In both groups (diabetic/control) CD3, CD4 expressions and CD4/CD8 ratio were decreased following the exercise, however expression of natural killer (NK) cells increased. Compared to type 1 diabetic patients healthy subjects had longer acute exercise that caused the increased level of CD8 expression, however type 1 diabetic patients did not show any difference. These results indicate that submaximal aerobic exercise might be recommended for type 1 diabetics without any complications because of its positive reflection on metabolic control and no negative effects on the immune system.

Magic rule for Al(n)H(m) magic clusters

Using the electronic shell closure criteria, we propose a new electron counting rule that enables us to predict the size, composition, and structure of many hitherto unknown magic clusters consisting of hydrogen and aluminum atoms. This rule, whose validity is established through a synergy between first-principles calculations and anion-photoelectron spectroscopy experiments, provides a powerful basis for searching magic clusters consisting of hydrogen and simple metal atoms.

Closo-alanes (Al4H4, AlnHn+2, 4 ≤ n ≤ 8): A New Chapter in Aluminum Hydride Chemistry

Anion photoelectron spectroscopy and density functional theory were employed to study aluminum hydride clusters, AlnHm- (4 <or= n <or= 8, 0 <or= m <or= 10). Photoelectron spectra revealed that Al4H4, Al4H6, and a family of species with general formula AlnHn+2 (5 <or= n <or= 8) have small adiabatic electron affinities and large HOMO-LUMO gaps (ranging from 0.5 to 1.9 eV) relative to those of their stoichiometric neighbors, implying their enhanced stabilities. Formulas reminiscent of boranes led us to investigate whether Wade's rules could be applied to alanes as well. DFT calculations showed that the AlnHn+2 (5 <or= n <or= 8) family adopts n-vertex polyhedral closo-structures with two extra hydrogen atoms occupying opposite bridging positions in agreement with the Wade's (n + 1) rule. These can be viewed as aluminum versions of hypothetical diprotonated closo-borane dianions (BnHn2- + 2H+). In addition, Al4H4 assumes a closo-tetrahedral geometry, while Al4H6 takes on a distorted tetrahedral (D2d) structure with two counter-positioned bridging hydrogen atoms and has the largest HOMO-LUMO gap (1.9 eV) of all the alanes we studied. All of these species can be understood in terms of underlying polyhedral skeletal electron pair theory (PSEPT) concepts. Although, the herein studied alanes do not have direct borane analogues, the ability to understand their structures in terms of the Wade-Mingos rules and the underlying PSEPT concepts suggests that they can be considered as borane analogues, thereby opening a new chapter in aluminum hydride chemistry.

Unexpected Stability of Al4H6: A Borane Analog?

Whereas boron has many hydrides, aluminum has been thought to exhibit relatively few. A combined anion photoelectron and density functional theory computational study of the Al4H-6 anion and its corresponding neutral, Al4H6, showed that Al4H6 can be understood in terms of the Wade-Mingos rules for electron counting, suggesting that it may be a borane analog. The data support an Al4H6 structure with a distorted tetrahedral aluminum atom framework, four terminal Al-H bonds, and two sets of counter-positioned Al-H-Al bridging bonds. The large gap between the highest occupied and the lowest unoccupied molecular orbitals found for Al4H6, together with its exceptionally high heat of combustion, further suggests that Al4H6 may be an important energetic material if it can be prepared in bulk.

Peritransplant and long-term secretion of interleukin-1beta in cyclosporine treated syngeneic rats allografted with islets of langerhans

Interleukin-1beta (IL-1beta) is one of the proinflammatory cytokines that may mediate primary nonfunction of islets of Langerhans, limiting the success of allogeneic transplantation. The aim of this study was to assess differences between the secretion of IL-1beta as well as glycemia in peri- and long-term periods of intraportal islet allo-transplantation with or without cyclosporine (CyA) immunosuppression. Inbred Wistar albino rats were transplanted intraportally with rat islets isolated by collagenase digestion. The two recipient groups (6 rats/group) were: group 1, control, islet transplantation (ITX) without any treatment and group 2, CyA-treated via the femoral muscle on days -1, 0, +1, and +2. Serum IL-1beta (pg/mL) levels were measured by ELISA on days 0 (pre-ITX), +1, +2, and +195. Tail vein blood was used to evaluate glycemia (mg/dL). No major differences were observed in IL-1beta secretion on days 0, +1, or +195 between the groups. Immunosuppressive treatment produced significantly lower secretion in group 2 (P < .002) on day +2. Significantly greater secretions were detected at days +195, +1, and +195 compared to days 0, +2, and +2, respectively (P < .002; P < .008; P < .002). Positive correlations were observed between IL-1beta levels on days +1 and +2 (r = 0.845, P < .034). The mean values in groups 1 and 2 on days 0, +1, and +2 were 140.6 +/- 4.62 vs 119.1 +/- 12.12, 73.1 +/- 19.59 vs 88.3 +/- 14.08, 106.5 +/- 13.79 vs 92.5 +/- 15.8, respectively. No animal in group 1 displayed glycemia while three group 2 animals did at day +195. However, a negative correlation was found between IL-1beta on day 0 and glycemia on day +195 (r = -0.999, P < .026). Our results suggest that IL-1beta secretion, which is detrimental for islet engraftment, decreases at peritransplant day +2, but is upregulated during long-term graft survival both in controls and in CyA-treated recipients.

Effect of human somatotropin hormone on cultured rat islets

Because growth hormone (GH) improves the insulin secretion capacity of isolated human fetal islets in vitro, we sought to show that it positively influences isolated rat islets. Islets isolated from Wistar albino rats by a modified automated system were cultured in media containing 87% RPMI 1640, 10% FCS, 2% antibiotic-antimycotic, and 1% L-glutamine for 12 +/- 2 days. The cultured islets were divided into two groups: growth hormone negative (Group I) and growth hormone positive (Group II). On the 5th day we observed a decrease in the islet cell counts in both groups (Group I 28% versus Group II 45%). On the 10th day, the decrease continued in the GH-negative group (59%), while the count remained stable in the GH-positive group. The viability of rat islets was determined by fluorescein diacetate (FDA) plus propidium iodide (PI) staining. In comparison to the peripheral green, central orange-red staining pattern of Group I islets upon fluorescent microscopy, Group II showed more compact islets. Cultured islets seemed to be brighter than those without GH in the cultured islets. In conclusion, we observed that 2 weeks of incubation in the presence of GH acts positively on cultured rat islets for both their amount and their viability.

Ab initio study of small graphitic cones with triangle, square, and pentagon apex

Accurate geometries of carbon nanocones of different sizes with a triangle, square or pentagon at the apex have been determined for the first time using a quantum chemical optimization method. The structure close to the apex is distorted from an ideal conical surface. The charging effect of the central defect is quite different from that predicted by tight-binding calculations. The symmetry behavior of the frontier orbitals and the size of the highest occupied molecular orbital-lowest unoccupied molecular orbital gap versus cone type and size is explained. The density of states quickly converges towards that of graphite when the size of the cone increases. In comparison to previous results in the literature it is found that the local densities of states of cones, that are locally different but belong to the same topo-combinatoric class, share common features.

Effects of pneumoperitoneum created through CO 2 insufflation and parameters of mechanical ventilation (PEEP application) on systemic dissemination of intraabdominal infections

BACKGROUND

To examine whether CO2 pneumoperitoneum and positive end expiratory pressure (PEEP) in mechanical ventilation affect the systemic spread of intraabdominal infection.

METHODS

Sprague-Dawley male rats weighing 200-300 g were allocated to three groups of 12 animals in each. All rats received mechanical ventilation under general anesthesia. An intraabdominal infection model was established by injecting with 1 ml of Escherichia coli (10(9) CFU/mL) intraperitoneally. Half of the animals in each group were exposed to PEEP (10 cmH2O). CO2 pneumoperitoneum at 13 mmHg was applied to the rats in group 1. Group 2 rats underwent laparotomy. Group 3 served as controls. In addition, TNF-alpha serum levels were measured at baseline and 3 h. A peritoneal specimen for histopathological examination were obtained after the rats were killed at the end of 3 h. For the assessment of data, descriptive statistical methods (mean, standard deviation) as well as Friedman test for repeated measurements in multiple groups, Kruskal-Wallis test for intergroup comparisons, Dunn's multiple comparison test for subgroup comparisons, Mann-Whitney U test for comparisons between paired groups, chi-square and Fisher's exact test for comparison of qualitative data, and McNemar's test for assessment of changes in group variables over time were used. The results were considered statistically significant if probability (p) values were <0.05.

RESULTS

Grades of peritonitis in group 1 and 2 were seen to differ nonsignificantly. In group 1, baseline blood cultures were not included in the assessment between the subgroups that received PEEP or not, as there was no growth in any of the subgroups. No significant difference was detected between growth in blood cultures at 1, 2, and 3 h ( p > 0.05). Application of PEEP in subgroups did not alter the blood culture results ( p > 0.05). Significant differences were seen between the initial and final TNF-alpha values of groups (KW: 18.94, p < 0.0001). The values in control group were observed to be significantly lower than those in groups 1 and 2 ( p < 0.01, p < 0.001). Bacteremia and systemic spread of the intraabdominal infection did appear to be different according to the PEEP application. After the assessments of ventilation parameters in our study, significant reductions in pH and HCO3 levels were detected in group 1 as a result of pneumoperitoneum, which was consistent with the literature. There is a significant difference between pH values at baseline and at the end of 1 h because of pneumoperitoneum (Fr: 10.01, p < 0.05). PEEP application in subgroups did not create significant differences in terms of respiratory parameters ( p < 0.01).

CONCLUSION

No difference was found between the applications of CO2 pneumoperitoneum and laparotomy with regard to bacteremia and infection-induced peritonitis. It was determined that pneumoperitoneum along with PEEP application had neither a positive nor a negative impact on intraabdominal infection.

Dissected nucleus-independent chemical shift analysis of pi-aromaticity and antiaromaticity

[structure: see text] Analysis of the basic pi-aromatic (benzene) and antiaromatic (cyclobutadiene) systems by dissected nucleus-independent chemical shifts (NICS) shows the contrasting diatropic and paratropic effects, but also reveals subtleties and unexpected details.

Which electron count rules are needed for four-center three-dimensional aromaticity?

A series of charged and neutral four-center n-electron (4c-ne, n = 1-4) molecules based on the adamantane framework, but which include combinations of boron, nitrogen, and phosphorus atoms at bridgehead positions, were studied computationally at the B3LYP/6-31G* level of density functional theory (DFT). The three-dimensional aromaticity, observed earlier for the 1,3,5,7-bisdehydroadamantane dication (1), is found to be general for 4c-2e electron systems. The degree of electron delocalization, evaluated by energetic, geometric, and various magnetic criteria, is quite independent of the molecular symmetry (point groups vary from Td to Cs), the degeneracy of the orbitals, the molecular charges, and the nature of the atoms participating in the delocalized bonding. Although the multiple positive (e.g., in 1 and some of the heteroatom systems) and multiple negative charges are strongly repulsive, the rigid adamantane frameworks help hold the bridgehead atoms within bonding distances with the fewer available electrons. The corresponding 4c-1e doublets are approximately half as aromatic as the 4c-2e singlets based on the same criteria. However, the three-electron systems may either adopt distorted but still four-center delocalized structures, or alternative 3c-2e two-dimensional arrangements in which the fourth bridgehead atom is more distant. There is no need to derive special rules for each point group for 4c-ne systems. Although the three-dimensional stabilization is computed to be quite appreciable, ranging between 10 and 50 kcalmol(-1), this delocalization energy is generally not sufficient to overcome distortion due to strain in higher homologues of 1 and in analogous noncage systems. Among the various 4c-2e homoadamantanedehydro dications studied, only the 1,8-dehydrohomoadamandiyl-3,6-dication forms a three-dimensional aromatic system.