Rupture of a flow aneurysm secondary to spontaneous extracranial to intracranial revascularisation in the posterior fossa following radiation-induced vasculopathy for cerebellar tumour

Paediatric patients receiving cranial irradiation therapy for brain tumours are at increased risk of cerebrovascular complications. Radiation-induced moyamoya syndrome (MMS) is a well-recognised complication of this. We present a case of an 8-year-old boy with a history of medulloblastoma, who underwent surgical excision followed by post-operative adjuvant oncological treatment. Six years later, he developed cerebellar/intraventricular haemorrhage. He underwent an emergency external ventricular drain (EVD) insertion followed by posterior fossa suboccipital craniotomy. On dural opening, an abnormal vessel was visualised on the surface of the right cerebellar hemisphere, which was not disturbed. No obvious abnormalities were identified intra-operatively. Cerebral catheter angiography confirmed the presence of a right-sided occipital artery (OA) to posterior inferior cerebellar artery (PICA) extracranial to intracranial (EC-IC) bypass with a zone of the distal PICA territory supplied by this EC-IC bypass. A presumed flow aneurysm originated from the bypass in the distal PICA, identified as cause for the haemorrhage. We highlight a rare cause for intracranial haemorrhage in this cohort of patients. Children who have undergone radiotherapy may have exquisitely sensitive cerebral vasculature and need careful vigilance and evaluation for vasculopathic complications following spontaneous haemorrhage.

Lactic Acidosis: A Novel Presentation of Intravascular Lymphoma

Intravascular large B-cell lymphoma (IVLBCL) is a rare form of diffuse large B-cell lymphoma that preferentially grows intravascularly within the capillaries and often has a fatal course. Most of the patients have advanced and disseminated disease at the time of presentation. It is often arduous to make the diagnosis during the antemortem period due to the multitude of presenting symptoms. We report a case of aggressive IVLBCL which presented with a myriad of complaints and acidosis and had a rapid clinical decline.

Impact of protein-energy malnutrition on outcomes of patients with diffuse large B cell lymphoma admitted for inpatient chemotherapy

Background

Protein-energy malnutrition (PEM) is a major factor contributing to morbidity and mortality in cancer patients. Empiric data are limited on the effect of PEM on the outcomes of patients receiving chemotherapy in diffuse large B cell lymphoma (DLBCL).

Methods

A retrospective cohort study was designed using data from the National Inpatient Sample for 2016 to 2019. Adult patients admitted for chemotherapy with DLBCL were stratified based on the presence of PEM. Primary outcomes assessed were mortality, length of stay, and total hospital charges.

Results

PEM was associated with an increased odds of mortality, 2.21% vs 0.25% (adjusted odds ratio 8.20, P < 0.001, 95% confidence interval [CI] 4.92-13.69). There was also an increased length of stay in patients with PEM, 7.89 vs 4.85 days (adjusted difference of 3.01 days, P < 0.001, 95% CI 2.37-3.66), as well as an increase in total charges, $137,940 vs $69,744 (adjusted difference of $65,427, P < 0.001, 95% CI $38,075-$92,778). Similarly, the presence of PEM was associated with increased odds of several secondary outcomes measured, including neutropenia, Candida sepsis, septic shock, acute respiratory failure, and acute kidney injury compared to the other cohort.

Conclusion

This study demonstrated an eightfold increased odds of mortality and concomitant prolonged length of stay with a 50% total charge increment in malnourished individuals with DLBCL compared to those without PEM. Prospective trials to evaluate PEM as an independent prognostic marker of chemotherapy tolerance and adequate nutritional support can improve clinical outcomes.

Impurity metallic conduction below the critical concentration of metal-insulator transition in Fe1-xCoxSi

Analysis on very detailed measurements of resistivity (ρ) and thermoelectric power (S) of magnetic impurity (Co) substituted iron silicide (FeSi) has been presented in this report. The impurity valence electrons of Co dominate the whole physical properties at low temperatures below 35 K, below the critical concentrationx_c(≈0.02). The negative thermopower and the positive slope in the resistivity at low temperatures are exciting and show that the system is not entirely insulator below the critical concentration of metal-insulator transition (x_c). So, due to the external impurity electrons, the system's magnetic ground state could change considerably compared to the parent compound FeSi. This report may help unveil the interesting low-temperature transport properties betweenx= 0 andx= 0.04 (Fe1-xCo_xSi). Two band model and variable range hopping model were employed to explain the low-temperature electrical and thermal transport properties.

Histopathologic differences between adult and pediatric patients with chronic rhinosinusitis

BACKGROUND

Adult and pediatric patients with chronic rhinosinusitis (CRS) may have differing philosophies in therapeutic management. Few studies have examined sinonasal tissue-level comparisons of these groups. This study examines histopathologic differences between children and adults with CRS, with the goal of understanding disease pathogenesis and optimizing medical management for both populations.

METHODS

In a retrospective cohort of CRS patients who underwent functional endoscopic sinus surgery (FESS), demographic factors, pertinent comorbidities, and a structured histopathologic report of 13 variables were compared across pediatric and adult CRS patients with and without nasal polyps (pCRSwNP, pCRSsNP, aCRSwNP, aCRSsNP, respectively).

RESULTS

A total of 378 adult (181 aCRSsNP, 197 aCRSwNP) and 50 pediatric (28 pCRSsNP, 22 pCRSwNP) patients were analyzed. Significantly more children compared with adults had a comorbid asthma diagnosis (64.5% vs. 37.2%, p = 0.003). Adults with CRS exhibited significantly more tissue neutrophilia (28.9% vs. 12.0%, p = 0.006), basement membrane thickening (70.3% vs. 44.0%, p < 0.001), subepithelial edema (61% vs. 30.0%, p < 0.001), squamous metaplasia (22.0% vs. 4.0%, p < 0.001), and eosinophil aggregates (22.8% vs. 4.0%, p < 0.001) than children with CRS. The majority (66.5%) of adult CRS patients exhibited a lymphoplasmacytic-predominant inflammatory background, whereas the majority (57.8%) of children with CRS exhibited a lymphocyte-predominant inflammatory background.

CONCLUSIONS

Sinonasal tissue of adult and pediatric CRS patients demonstrates clear histopathologic differences. Our findings provide insight into differing pathophysiology, which may enable optimization of targeted therapies for patients in each of these unique clinical groups.

Robiquetia gracilis (Lindl.) Garay—a new record to the flora of Anamalai Hills, Tamil Nadu, India

Robiquetia gracilis (Lindl.) Garay a rare orchid species was collected from Anamalai hills, Tamil Nadu, a new report to the flora of the hills. A detailed description with colour photos and relevant notes are provided.

Chemometric Access for RP-HPLC Simultaneous Estimation of Tadalafil and Dapoxetine Applying Response Surface Methodology

Aims: A RP-HPLC method was developed and validated for simultaneous estimation of Tadalafil and Dapoxetine applying statistical experimental design. Methodology: Multivariate optimization of the experimental conditions of RP-HPLC method was using Design of experiments. Independent three factors like phosphate buffer pH, mobile phase composition and flow rate were applied to design mathematical models. To study the response surface methodology by using Central composite design (CCD). In depth the effects of these independent factors was studied using CCD. Simultaneously optimize the retention time and resolution of the analytes was applying Desirability function. Results: The predicted and optimized data from contour picture containing phosphate buffer (pH 3.4) and acetonitrile in the ratio of 40:60%v/v respectively. Flow rate was found to be 0.8 ml/min. Baseline separation of both analytes with run time of less than 10.0 min and good resolution were achieved using these optimum conditions. Conclusion: Method was validated according to ICH guidelines by using optimized assay conditions. Therefore, the reports distinctly indicated that Quality by design access could be satisfactorily used to optimize RP-HPLC method for simultaneous estimation of Tadalafil and Dapoxetine.

In-vitro Cytoprotective Activity of Eichhornia crassipes Flowers Against Hydrogen Peroxideinduced Oxidative Stress in BRL 3A Rat Liver Cells

The aim of this study was to investigate the cytoprotective effect of ethanol extract of Eichhornia crassipes flowersand its fractions against hydrogen peroxide induced oxidative stress in BRL 3A liver cells. Powdered flowers of Eichhornia crassipeswere subjected to hot continuous extraction in soxhlet extractor using ethanol as solvent material. Initially, the solvent extracts were subjected to qualitative, quantitative analysis and assessed for in-vitro free radical scavenging activity and anti-oxidant activity. The ethanol extract was fractionated using benzene, chloroform and n-butanol. The crude ethanol extract and its fractions were evaluated for its potential cytoprotective effect against hydrogen peroxide (H2O2) induced oxidative stress in BRL 3A cell lines.Biochemical assays were carried out to determine the cytoprotective activity, including cell viability, lipid peroxidation by determining the formation of malondialdehyde, lactate dehydrogenase leakage into culture medium, the catalase activity and the content of reduced glutathione (GSH) in the cells. Exposure of BRL 3A to 2mM H2O2 reduced the cell viability, increased the malondialdehyde (MDA) level, increased the leakage of lactate dehydrogenase (LDH) and caused reduction in antioxidant activities. Pretreatment of cultured cells with crude ethanol extract of Eichhornia crassipes flowers and different solvent fractions at concentrations 0.01, 0.1, 1, 10, 100 μg/ml for 30 minutes before H2O2 exposure attenuated the oxidative injury in dose-dependent manner. It was observed that crude ethanol extract of Eichhornia crassipes flowers exhibited a strong cytoprotective by increasing cell viability, decreasing lipid peroxidation and LDH leakage. Further increase in catalase and reduced glutathione activity was noted in the cells pre-treated with ethanol extract of Eichhornia crassipes flowers. These findings suggest that ethanol extract of Eichhornia crassipes flowers has a strong cytoprotective activity against oxidative injury caused by reactive oxygen species.

Glutamatergic dysfunction in resistant obsessive-compulsive disorder: An auditory mismatch negativity study

Introduction

Obsessive-compulsive disorder (OCD) patients with poor response to serotonin reuptake inhibitors (SRIs) may have dysfunction involving other neurotransmitters, including glutamate. Mismatch negativity (MMN), an event-related potential dependent on glutamatergic functioning, has not been studied in the adult OCD population and SRI non-responders.

Objectives

To compare the amplitude of MMN between OCD subjects who have responded(R) and not responded(NR) to SRIs, with healthy volunteers(HV).

Methods

MMN was measured in 15 OCD subjects fulfilling DSM-IV criteria (8 non-responders and 7 responders) and 22 healthy volunteers. Auditory MMN was measured using a multi-feature paradigm consisting of two variants each in frequency, duration, and intensity domains. EEG was recorded using 64 channel electrodes at 1000Hz. Epochs of 700 ms were extracted for each stimulus. MMN was evaluated as peak difference between the deviant and standard stimulus. MMN amplitudes at Fz were used for comparison between the groups using Kruskal-Wallis test followed by posthoc analysis, with significance set at p<0.05.

Results

There was no significant difference in age/gender distribution between the three groups and duration of illness between the two OCD groups. There was a significant difference in MMN amplitude of a frequency deviant between the three groups (H=7.312,P=0.026). Post-hoc pairwise analyses revealed a significant reduction in MMN amplitude in NRs as compared to the HV group (H=10.9,P=0.04).

Conclusions

The results are suggestive of glutamatergic dysfunction in OCD subjects with poor response to SRIs. The findings have to be replicated in larger samples employing other paradigms to evaluate glutamatergic functioning and have future potential in understanding treatment response to SRIs.

Optimal tuning of PID controller in time delay system: a review on various optimization techniques

The processes which contain at least one pole at the origin are known as integrating systems. The process output varies continuously with time at certain speed when they are disturbed from the equilibrium operating point by any environment disturbance/change in input conditions and thus they are considered as non-self-regulating. In most occasions this phenomenon is very disadvantageous and dangerous. Therefore it is always a challenging task to efficient control such kind of processes. Depending upon the number of poles present at the origin and also on the location of other poles in transfer function different types of integrating systems exist. Stable first order plus time delay systems with an integrator (FOPTDI), unstable first order plus time delay systems with an integrator (UFOPTDI), pure integrating plus time delay (PIPTD) systems and double integrating plus time delay (DIPTD) systems are the classifications of integrating systems. By using a well-controlled positioning stage the advances in micro and nano metrology are inevitable in order satisfy the need to maintain the product quality of miniaturized components. As proportional-integral-derivative (PID) controllers are very simple to tune, easy to understand and robust in control they are widely implemented in many of the chemical process industries. In industries this PID control is the most common control algorithm used and also this has been universally accepted in industrial control. In a wide range of operating conditions the popularity of PID controllers can be attributed partly to their robust performance and partly to their functional simplicity which allows engineers to operate them in a simple, straight forward manner. One of the accepted control algorithms by the process industries is the PID control. However, in order to accomplish high precision positioning performance and to build a robust controller tuning of the key parameters in a PID controller is most inevitable. Therefore, for PID controllers many tuning methods are proposed. the main factors that lead to lifetime reduction in gain loss of PID parameters are described in This paper and also the main methods used for gain tuning based on optimization approach analysis is reviewed. The advantages and disadvantages of each one are outlined and some future directions for research are analyzed.

Unconventional impurity band conduction and carrier dynamics in Ni substituted FeSi

Analysis of the resistivity, thermoelectric power, and heat capacity of Fe1-xNixSi is presented in this report. In-spite of Ni having two extra valence electrons as compared to Fe, the physical properties are observed to be dominated by holes. In this report, we have explained this unusual hole dominant scenario by a modified two narrow-band model. According to this model, the impurity electrons which are nearer to conduction band get shifted towards lower energy level thereby leaving holes around the Fermi level, and hence a hole dominated scenario at low temperatures. Due to this hole like density of states around the Fermi level, the nickel substitution could only produce a weak ferromagnetic behavior. Such a picture may assist in understanding the thermopower of similar systems i.e. Ni substituted on Fe site, such as Fe2-xNixVAl. We have also found that the activation energy derived from resistivity and thermoelectric power decreases with increasing Ni concentration.

Anomalous magnetic properties of RCrTiO5 (R = Dy and Ho) compounds

We have investigated the nature of magnetic ground state of RCrTiO₅ (R  =  Dy and Ho) through dc magnetization and heat capacity measurements. Due to the strong competition between the Cr³⁺ and R ³⁺ sublattice moments, several intriguing phenomena have been observed when the magnetic state is probed at low field. In both the systems, the Cr³⁺ sublattice undergoes a long-range antiferromagnetic ordering below  ∼139 K with a weak ferromagnetic (FM) moment perpendicular to c axis as evident from the hysteresis in M(H) curve. At low fields ([Formula: see text]150 Oe), the zero-field-cooled magnetization shows that the FM component of Cr³⁺ spin and R ³⁺ moments align in the opposite direction with respect to each other and the net moment aligns in the opposite direction to the applied field in the temperature range 136-16 K for DyCrTiO₅ and below 128 K for HoCrTiO₅. For both the samples, the strong coupling between the two magnetic sublattices is manifested in the temperature dependence of coercive field. Another interesting phenomenon, the spin reorientation transition, has been observed below [Formula: see text] K, where the easy axis of FM moment of Cr³⁺ starts to rotate from one crystallographic axis toward another in DyCrTiO₅ but no such transition has been observed in HoCrTiO₅. The other members of RCrTiO₅ series do not show such kinds of interesting magnetic properties.

Expanding the Distinctive Neuroimaging Phenotype of ACTA2 Mutations

BACKGROUND AND PURPOSE

Arg179His mutations in ACTA2 are associated with a distinctive neurovascular phenotype characterized by a straight course of intracranial arteries, absent basal Moyamoya collaterals, dilation of the proximal internal carotid arteries, and occlusive disease of the terminal internal carotid arteries. We now add to the distinctive neuroimaging features in these patients by describing their unique constellation of brain malformative findings that could flag the diagnosis in cases in which targeted cerebrovascular imaging has not been performed.

MATERIALS AND METHODS

Neuroimaging studies from 13 patients with heterozygous Arg179His mutations in ACTA2 and 1 patient with pathognomonic clinicoradiologic findings for ACTA2 mutation were retrospectively reviewed. The presence and localization of brain malformations and other abnormal brain MR imaging findings are reported.

RESULTS

Characteristics bending and hypoplasia of the anterior corpus callosum, apparent absence of the anterior gyrus cinguli, and radial frontal gyration were present in 100% of the patients; flattening of the pons on the midline and multiple indentations in the lateral surface of the pons were demonstrated in 93% of the patients; and apparent "squeezing" of the cerebral peduncles in 85% of the patients.

CONCLUSIONS

Because α-actin is not expressed in the brain parenchyma, only in vascular tissue, we speculate that rather than a true malformative process, these findings represent a deformation of the brain during development related to the mechanical interaction with rigid arteries during the embryogenesis.

Quantum phase transition and non-Fermi liquid behavior in Fe1-x Co x Si (x ⩾ 0.7)

We report on the nature of electron correlations in Fe_1-x Co _x Si ([Formula: see text]) using combined results of magnetization, specific heat and transport properties. Doping driven quantum critical point is observed to occur at [Formula: see text]. The magnetically unstable regime is identified to be centered around [Formula: see text] [[Formula: see text]]. The emergence of non-Fermi liquid behaviors in x  =  0.8 (near to ferromagnetic quantum critical point) and x  =  0.9 (disorder-induced) compositions are discussed on the basis of the power-law dependence of susceptibility [Formula: see text] ([Formula: see text] for x  =  0.8 and 0.55 for x  =  0.9), specific heat [Formula: see text] ([Formula: see text] for x  =  0.8 and 0.9) and resistivity [Formula: see text] ([Formula: see text] for x  =  0.8 and 1.38 for x  =  0.9). Further, a comprehensive classification of doping dependent physical properties of Fe_1-x Co _x Si is presented in the revisited temperature-composition (T-x) phase diagram.

Electrochemically synthesized faceted CuInTe2nanorods as an electron source for field emission applications

Cyclic voltammogram recorded for CuInTe₂in aqueous electrolyte and chronoamperometry curve obtained during electrodeposition.

Spin reorientation and disordered rare earth magnetism in Ho2FeCoO6

We report the experimental observation of spin reorientation in the double perovskite Ho₂FeCoO₆. The magnetic phase transitions in this compound are characterized and studied through magnetization and specific heat, and the magnetic structures are elucidated through neutron powder diffraction. Two magnetic phase transitions are observed in this compound-one at [Formula: see text] K, from paramagnetic to antiferromagnetic, and the other at [Formula: see text] K, from a phase with mixed magnetic structures to a single phase through a spin reorientation process. The magnetic structure in the temperature range 200-45 K is a mixed phase of the irreducible representations [Formula: see text] and [Formula: see text], both of which are antiferromagnetic. The phase with mixed magnetic structures that exists in Ho₂FeCoO₆ gives rise to a large thermal hysteresis in magnetization that extends from 200 K down to the spin reorientation temperature. At T _N2, the magnetic structure transforms to [Formula: see text]. Though long-range magnetic order is established in the transition metal lattice, it is seen that only short-range magnetic order prevails in the Ho³⁺ lattice. Our results should motivate further detailed studies on single crystals in order to explore the spin reorientation process, spin switching and the possibility of anisotropic magnetic interactions giving rise to electric polarization in Ho₂FeCoO₆.

Novel biallelic SZT2 mutations in 3 cases of early-onset epileptic encephalopathy

The seizure threshold 2 (SZT2) gene encodes a large, highly conserved protein that is associated with epileptogenesis. In mice, Szt2 is abundantly expressed in the central nervous system. Recently, biallelic SZT2 mutations were found in 7 patients (from 5 families) presenting with epileptic encephalopathy with dysmorphic features and/or non-syndromic intellectual disabilities. In this study, we identified by whole-exome sequencing compound heterozygous SZT2 mutations in 3 patients with early-onset epileptic encephalopathies. Six novel SZT2 mutations were found, including 3 truncating, 1 splice site and 2 missense mutations. The splice-site mutation resulted in skipping of exon 20 and was associated with a premature stop codon. All individuals presented with seizures, severe developmental delay and intellectual disabilities with high variability. Brain MRIs revealed a characteristic thick and short corpus callosum or a persistent cavum septum pellucidum in each of the 2 cases. Interestingly, in the third case, born to consanguineous parents, had unexpected compound heterozygous missense mutations. She showed microcephaly despite the other case and previous ones presenting with macrocephaly, suggesting that SZT2 mutations might affect head size.

Cortical Inhibition in Symptomatic and Remitted Mania Compared to Healthy Subjects: A Paired-pulse TMS Study

Introduction

Cortical inhibition (CI) is a neurophysiological outcome of the interaction between GABA inhibitory interneurons and other excitatory neurons. Transcranial magnetic stimulation (TMS) measures of CI deficits have been documented in both symptomatic and remitted bipolar disorder (BD) suggesting it could be a trait marker. The effects of medications and duration of illness may contribute to these findings.

Objective

To study CI in BD.

Aims

To compare CI across early-course medication-naive BD-mania, remitted first episode mania (FEM) and healthy subjects (HS).

Methods

Symptomatic BD subjects having < 3 episodes, currently in mania and medication-naive (n = 27), remitted FEM (n = 27; YMRS < 12 and HDRS < 8) and 45 HS, matched for age and gender, were investigated. Resting motor threshold (RMT) and 1-millivolt motor threshold (MT1) were estimated from the right first dorsal interosseous muscle. Paired-pulse TMS measures of short (SICI; 3ms) and long interval intracortical inhibition (LICI; 100ms) were acquired. Group differences in measures of CI were examined using ANOVA.

Results

Table 1.

Conclusions

Symptomatic mania patients had the highest motor thresholds and the maximum LICI indicating a state of an excessive GABA-B neurotransmitter tone. Remitted mania patients had deficits in SICI indicating reduced GABA-A neurotransmitter tone. Putative changes in GABA-A neurotransmitter system activity with treatment may be investigated in future studies. CI has received less attention in BD as compared to schizophrenia and is a potential avenue for future research in this area.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Effects of Mn Doping on Zinc Oxide Films Prepared by Spray Pyrolysis Technique

The work deals with the preparation of Zinc Oxide (ZnO) thin films on microscopic glass substrate by spray pyrolysis technique. The systematic study on the influence of Mn doping up to 15% has been performed. The structural studies revealed that pure and doped film has hexagonal structure. In order to reduce the internal strain due to Mn doping, the crystallite size decreases. The atomic force microscopy (AFM) measurement shows the decrease in grain size and roughness with doping. The resistivity curve shows a clear hump corresponding to smaller Mn doping ([Formula: see text]) around [Formula: see text]. This hump was found to reduce with the increase in Mn concentration and for [Formula: see text], beyond which it vanishes completely. This is attributed to critical behavior of resistivity and may be due to the scattering of carriers by magnetic spin fluctuation via exchange interaction. The optical measurement shows the shift in absorption edge of Mn doped ZnO films toward the longer wavelength side. This correlates the reduction in grain size as a function of Mn concentration. The optical bandgap goes down, whereas refractive index increases with dopant concentration.

Correction: Charge transport mechanisms in sol-gel grown La0.7Pb0.3MnO3/LaAlO3 manganite films

Correction for 'Charge transport mechanisms in sol-gel grown La_0.7Pb_0.3MnO₃/LaAlO₃ manganite films' by Eesh Vaghela et al., Phys. Chem. Chem. Phys., 2017, DOI: 10.1039/c6cp07730g.

Charge transport mechanisms in sol-gel grown La0.7Pb0.3MnO3/LaAlO3 manganite films

In this communication, structural, microstructural, transport and magnetotransport properties are reported for La_0.7Pb_0.3MnO₃/LaAlO₃ (LPMO/LAO) manganite films having different thicknesses. All the films were irradiated with 200 MeV Ag⁺¹⁵ swift heavy ions (SHI). Films were grown using the sol-gel method by employing the acetate precursor route. Structural measurements were carried out using the X-ray diffraction (XRD) method at room temperature, while atomic force microscopy (AFM) was performed for the surface morphology. Temperature dependent resistivity under different applied magnetic fields for all the films shows metal to insulator transition at temperature T_P. In addition to the metal to insulator transition at T_P, the films also exhibit low temperature resistivity upturn behavior. Resistivity, T_P and upturn behavior are highly influenced by the film thickness, applied magnetic field and irradiation. To understand the nature of charge transport for the low temperature resistivity behavior and metallic and insulating (semiconducting) regions, various models and mechanisms have been verified and the most suitable mechanism has been found for each region in the resistivity curves. Magnetoresistance (MR) is affected by temperature, film thickness and irradiation. MR behavior has been understood in terms of combined and separate contributions from grains and grain boundaries in the films.

Assessment of body force effects in flow condensation, part II: Criteria for negating influence of gravity

This study concerns the development of a set of mechanistic criteria capable of predicting the flow conditions for which gravity independent flow condensation heat transfer can be achieved. Using FC-72 as working fluid, a control-volume based annular flow model is solved numerically to provide information regarding the magnitude of different forces acting on the liquid film and identify which forces are dominant for different flow conditions. Separating the influence of body force into two components, one parallel to flow direction and one perpendicular, conclusions drawn from the force term comparison are used to model limiting cases, which are interpreted as transition points for gravity independence. Experimental results for vertical upflow, vertical downflow, and horizontal flow condensation heat transfer coefficients are presented, and show that, for the given test section, mass velocities above 425 kg/m2 s ensure gravity independent heat transfer. Parametric evaluation of the criteria using different assumed values of mass velocity, orientation, local acceleration, and exit quality show that the criteria obey physically verifiable trends in line with those exhibited by the experimental results. As an extension, the separated flow model is utilized to provide a more sophisticated approach to determining whether a given configuration will perform independent of gravity. Results from the model show good qualitative agreement with experimental results. Additionally, analysis of trends indicate use of the separated flow model captures physics missed by simpler approaches, demonstrating that use of the separated flow model with the gravity independence criteria constitute a powerful predictive tool for engineers concerned with ensuring gravity independent flow condensation heat transfer performance.

Disrupted nitric oxide signaling due to GUCY1A3 mutations increases risk for moyamoya disease, achalasia and hypertension

Moyamoya disease (MMD) is a progressive vasculopathy characterized by occlusion of the terminal portion of the internal carotid arteries and its branches, and the formation of compensatory moyamoya collateral vessels. Homozygous mutations in GUCY1A3 have been reported as a cause of MMD and achalasia. Probands (n = 96) from unrelated families underwent sequencing of GUCY1A3. Functional studies were performed to confirm the pathogenicity of identified GUCY1A3 variants. Two affected individuals from the unrelated families were found to have compound heterozygous mutations in GUCY1A3. MM041 was diagnosed with achalasia at 4 years of age, hypertension and MMD at 18 years of age. MM149 was diagnosed with MMD and hypertension at the age of 20 months. Both individuals carry one allele that is predicted to lead to haploinsufficiency and a second allele that is predicted to produce a mutated protein. Biochemical studies of one of these alleles, GUCY1A3 Cys517Tyr, showed that the mutant protein (a subunit of soluble guanylate cyclase) has a significantly blunted signaling response with exposure to nitric oxide (NO). GUCY1A3 missense and haploinsufficiency mutations disrupt NO signaling leading to MMD and hypertension, with or without achalasia.

Improved electrochromic performance of a radio frequency magnetron sputtered NiO thin film with high optical switching speed

A nickel oxide (NiO) thin film with better reversibility, high optical modulation, and enhanced coloration efficiency with fast switching time was prepared using radio frequency (rf) magnetron sputtering technique.

Effect of thermal annealing on the phase evolution of silver tungstate in Ag/WO₃ films

Silver/tungsten oxide multi-layer films are deposited over quartz substrates by RF magnetron sputtering technique and the films are annealed at temperatures 200, 400 and 600°C. The effect of thermal annealing on the phase evolution of silver tungstate phase in Ag/WO3 films is studied extensively using techniques like X-ray diffraction, micro-Raman analysis, atomic force microscopy and photoluminescence studies. The XRD pattern of the as-deposited film shows only the peaks of cubic phase of silver. The film annealed at 200°C shows the presence of XRD peaks corresponding to orthorhombic phase of Ag2WO4 and peaks corresponding to cubic phase of silver with reduced intensity. It is found that, as annealing temperature increases, the volume fraction of Ag decreases and that of Ag2WO4 phase increases and becomes highest at a temperature of 400°C. When the temperature increases beyond 400°C, the volume fraction of Ag2WO4 decreases, due to its decomposition into silver and oxygen deficient phase Ag2W4O13. The micro-Raman spectra of the annealed films show the characteristic bands of tungstate phase which is in agreement with XRD analysis. The surface morphology of the films studied by atomic force microscopy reveals that the particle size and r.m.s roughness are highest for the sample annealed at 400°C. In the photoluminescence study, the films with silver tungstate phase show an emission peak in blue region centered around the wavelength 441 nm (excitation wavelength 256 nm).

Two dimensional magnetic correlation in the unconventional corrugated layered oxides (Ba,Sr)₄Mn₃O₁₀

Both Ba4Mn3O10 and Sr4Mn3O10 crystallize in an orthorhombic crystal structure consisting of corrugated layers containing Mn3O12 polydedra. The thermal variation of magnetic susceptibility of the compositions consists of a broad hump like feature indicating the presence of low dimensional magnetic correlation. We have systematically investigated the magnetic data of these compounds and found that the experimental results match quite well with the two dimensional Heisenberg model of spin-spin interaction. The two dimensional nature of the magnetic spin-spin interaction is supported by the low temperature heat capacity data of Ba4Mn3O10. Interestingly, both the samples show dielectric anomaly near the magnetic ordering temperature indicating multiferroic behavior.

Changes in in-plane electrical conductivity of PEDOT:PSS thin films due to electric field induced dipolar reorientation

A model, based on induced reorientation of PEDOT:PSS chains due to electric field interaction with electric dipoles of the chains, has been proposed to explain observed resistivity switching and anisotropic in-plane conductivity in PEDOT:PSS films.

Structural, magnetic, and dielectric studies on Gd0.7Y0.3MnO3

Structural, magnetic, specific heat, and dielectric studies were carried out on Y substituted (30 at. %) GdMnO(3) compound as a function of temperature. Anomalies occur at ~41 and 18 K, in the specific heat measurements and are ascribed to paramagnetic, to sinusoidal incommensurate antiferromagnetic transition (ICAFM) and ICAFM to commensurate antiferromagnetic transitions, respectively. Changes in the lattice parameters across these temperatures indicate magneto-elastic coupling present in the compound. However, in the dielectric measurements, an anomaly at 18 K alone is observed and is ascribed to a ferroelectric transition, giving rise to spontaneous ferroelectric ordering at low temperatures. This observation is supported by an anomaly in lattice parameters, across the transition temperature. From the frequency dependent dielectric studies, a strong coupling between Gd(3+) and Mn(3+) magnetic sublattices is inferred and Y substitution results in substantial changes in the relaxation process compared to that of GdMnO(3).