Contact line dynamics of a water drop spreading over a textured surface in the electrowetting-on-dielectric configuration.

Modeling the electrowetting process of a liquid droplet placed on a hydrophobic surface in an ambient environment has several challenges over and above those of basic spreading [F. Mugele, Soft Matter 5, 3377 (2009)10.1039/b904493k]. At an external voltage below the value that causes contact angle saturation, transient spreading is augmented by contact angle reduction defined by the Young-Lippmann equation. In addition, the macroscopic equilibrium contact angle and, therefore, the spreading rate could be altered by the surface hysteresis. Beyond the saturation point, spreading reveals additional features of higher complexity [Q. Vo and T. Tran, J. Fluid Mech. 925, A19 (2021)10.1017/jfm.2021.677]. These details have been examined from experiments as well as numerical simulation in the present work. Below the saturation point, the contact angle model of Dwivedi et al. [Phys. Rev. Fluids 7, 034002 (2022)10.1103/PhysRevFluids.7.034002] with the correction related to the electric field is seen to be applicable. Beyond saturation, the experimentally determined instantaneous contact angle distribution shows two distinct functionalities with respect to the contact line velocity. The first prevails from the onset of spreading until the spreading factor attains a peak value. The second trend is initiated with the retraction of the contact line. Except for differences in parametric values, the form of the contact angle model remains unchanged. Simulations in the postsaturation regime are shown to match experimental data in terms of the transient spreading factor, drop shapes, and the instantaneous contact angle. The role of the ground wire is found to be important and the three-phase contact line formed on it has been included in simulations. Spreading dynamics of the droplet have also been studied when the ground wire is kept at a distance of 40 µm from the apex of the drop. Simulations as well as experiments, show the propagation of a capillary wave between the ground wire and the three-phase contact line. For spreading over an uncoated polydimethylsiloxane (PDMS) surface, the contact line is trapped at local pinning sites, leading to additional distortions in the instantaneous shapes acquired by the interface.

Direct impact of gonadotropins on glucose uptake and storage in preovulatory granulosa cells: Implications in the pathogenesis of polycystic ovary syndrome.

BACKGROUND: Polycystic ovary syndrome (PCOS) is often associated with higher levels of LH, and arrested ovarian follicular growth. The direct impact of high LH on FSH mediated metabolic responses in PCOS patients is not clearly understood. METHOD: In order to investigate the impact of FSH and LH on glucose metabolism in preovulatory granulosa cells (GCs), we used [U14C]-2 deoxyglucose, D-[U14C]-glucose or 2-NBD glucose to analyse glucose uptake and its incorporation into glycogen. To reproduce the high androgenic potential in PCOS patients, we administered hCG both in vitro and in vivo. The role of IRS-2/PI3K/Akt2 pathway was studied after knockdown with specific siRNA. Immunoprecipitation and specific assays were used for the assessment of IRS-2, glycogen synthase and protein phosphatase 1. Furthermore, we examined the in vivo effects of hCG on FSH mediated glycogen increase in normal and PCOS rat model. HEK293 cells co-expressing FSHR and LHR were used to demonstrate glucose uptake and BRET change by FSH and hCG. RESULTS: In normal human and rat granulosa cells, FSH is more potent than hCG in stimulating glucose uptake, however glycogen synthesis was significantly upregulated only by FSH through increase in activity of glycogen synthase via IRS-2/PI3K/Akt2 pathway. On the contrary, an impaired FSH-stimulated glucose uptake and glycogen synthesis in granulosa cells of PCOS-patients indicated a selective defect in FSHR activation. Further, in normal human granulosa cells, and in immature rat model, the impact of hCG on FSH responses was such that it inhibited the FSH-mediated glucose uptake as well as glycogen synthesis through inhibition of FSH-stimulated IRS-2 expression. These findings were further validated in HEK293 cells overexpressing Flag-LHR and HA-FSHR, where high hCG inhibited the FSH-stimulated glucose uptake. Notably, an increased BRET change was observed in HEK293 cells expressing FSHR-Rluc8 and LHR-Venus possibly suggesting increased heteromerization of LHR and FSHR in the presence of both hCG and FSH in comparison to FSH or hCG alone. CONCLUSION: Our findings confirm a selective attenuation of metabolic responses to FSH such as glucose uptake and glycogen synthesis by high activation level of LHR leading to the inhibition of IRS-2 pathway, resulting in depleted glycogen stores and follicular growth arrest in PCOS patients.

Electrowetting-on-Dielectric System for COVID-19 Testing.

The ongoing viral outbreak labeled COVID-19 is spreading rapidly across states and is posing a great threat to public health. Rapid identification of the virus in the population plays a crucial role in isolating the individual and breaking the transmission chain, apart from initiating an appropriate treatment procedure. Here, we discuss an electrowetting-on-dielectric (EWOD) technology that uses a microprocessor-controlled electrode array to merge a possibly infected sample carried by a liquid drop with a drop of a reagent to carry out the testing process. Changes in color occurring during the mixing process of the drops are imaged using a camera.

Cutaneous manifestations of diabetic peripheral neuropathy.

There is a rise in number of people diagnosed with Diabetes Mellitus. The incidence is rising in modern Indian society because of Industrial development and drastically changing lifestyles. Diabetic neuropathies are microvascular disorders that are usually associated with the duration of Diabetes. Among the various forms, the most common is Diabetic Peripheral Neuropathy. The disease if neglected leads to chronic ulcer formation leading to amputations frequently. Hence the aim of this study is to document the early cutaneous changes and create an early awareness in the importance of controlling Diabetes. The study consisted of 205 patients with Type 2 DM. Participant's neuropathy status was determined based on Neuropathy Disability Score and Diabetic Neuropathy Symptom Score. Among the Skin changes documented, the common changes seen were: Peripheral hair loss in 185 (90.2%), Xerosis in 168 (82%), Anhydrosis in 162 (79%), Plantar Fissures in 136 (66.3%), Plantar Ulcer in 80 (39%), common nail changes documented were Onychomycosis in 165 (80.5%) and Onychauxis in 53 (25.8%) patients in relation to the occupation and duration of Diabetes mellitus. In conclusion, it is important to control glycemic levels in the all stages of Diabetes and institute foot care measures to prevent the complications of neuropathy.

A phantom study on the behavior of Acuros XB algorithm in flattening filter free photon beams.

To study the behavior of Acuros XB algorithm for flattening filter free (FFF) photon beams in comparison with the anisotropic analytical algorithm (AAA) when applied to homogeneous and heterogeneous phantoms in conventional and RapidArc techniques. Acuros XB (Eclipse version 10.0, Varian Medical Systems, CA, USA) and AAA algorithms were used to calculate dose distributions for both 6X FFF and 10X FFF energies. RapidArc plans were created on Catphan phantom 504 and conventional plans on virtual homogeneous water phantom 30 × 30 × 30 cm(3), virtual heterogeneous phantom with various inserts and on solid water phantom with air cavity. Dose at various inserts with different densities were measured in both AAA and Acuros algorithms. The maximum % variation in dose was observed in (-944 HU) air insert and minimum in (85 HU) acrylic insert in both 6X FFF and 10X FFF photons. Less than 1% variation observed between -149 HU and 282 HU for both energies. At -40 HU and 765 HU Acuros behaved quite contrarily with 10X FFF. Maximum % variation in dose was observed in less HU values and minimum variation in higher HU values for both FFF energies. Global maximum dose observed at higher depths for Acuros for both energies compared with AAA. Increase in dose was observed with Acuros algorithm in almost all densities and decrease at few densities ranging from 282 to 643 HU values. Field size, depth, beam energy, and material density influenced the dose difference between two algorithms.

Small field dosimetry and analysis of flattening filter free beams in true beam system.

AIM OF STUDY: The purpose of this study was to report the dosimetric characteristics of the small fields in flattening filter free (FFF) beams (output measurements, profile analysis, surface dose and consistency) generated by medical linear accelerator and its variation with respect to flattened beams (FB). MATERIALS AND METHODS: Surface doses were obtained for field sizes 1 × 1-40 × 40 cm(2). Field width and penumbra were analyzed for field sizes 1 × 1-40 × 40 cm(2). To take output factors for small fields, diode and micro chamber were used and data was taken at a source-to-surface distance (SSD) and extended SSD. Consistency checked for the dosimetric data for 1 year. RESULTS: Surface doses were higher in FFF compared with FB up to 20 × 20 cm(2) field size. Measured field sizes were slightly lesser in FFF and penumbra values were increased with respect to field size in both FB and FFF. For small fields, diode values have shown more promising results than micro chamber. Small field output measurements at nominal SSD and extended SSD were well in agreement with each other. FFF beams showed good data consistency in 1 year duration. CONCLUSION: Small field dosimetry, surface dose, profile analysis and consistency of FFF beams in FFF photon beams were derived and data shown good consistency during 1 year duration.

A blast from the past!: The value of adding single slice magnetic resonance myelography sequence to magnetic resonance imaging of the spine; a flashback to the conventional myelography of the past.

BACKGROUND: The study was undertaken to determine whether a single slice magnetic resonance (MR) myelogram sequence improves the interpretation and diagnostic yield for magnetic resonance imaging (MRI) of the spine. METHODS: A total of 100 cases with positive findings were retrospectively reviewed. All patients had initial imaging with sagittal T1-weighted (T1-W) and T2-weighted (T2-W) scans, followed by axial T2-W images. Subsequently, a heavily T2-W single slice MR myelogram sequence was acquired in coronal and sagittal planes. The MR myelogram images were evaluated initially by a radiologist, and, further independently reviewed, by a neurologist, neurosurgeon, and spine surgeon. The utility of the MR myelogram in establishing the diagnosis was graded on a 4-point scale. RESULTS: Out of 100 cases, 53% showed degenerative spine or disc disease, 14% space occupying lesions, 13%, congenital lesions, 7% infection, and 7% other conditions. The MR myelogram contributed additional information in 50-74% cases. The intraclass correlation coefficient showed overall good agreement between observers in grading the utility of MR myelogram. CONCLUSION: Single slice MR myelography is noninvasive avoiding the complications associated with lumbar punctures/intrathecal contrast injections, while image acquisition takes only an added 6-8 s. Although MR myelogram has no value as a stand-alone sequence, its inherent advantage is that it completes the overview of the spinal pathology in entirety, and adds vital three-dimensional information in 50-74% of cases.

Commissioning and quality assurance of Calypso four-dimensional target localization system in linear accelerator facility.

Four dimensional (4D) target localization system (Calypso System) was installed at our hospital, which is equipped with Beacon Transponders, Console, Electromagnetic Array, Optical System, Tracking Station, Treatment table overlay, and Calypso kVue Couch top. The objective of this presentation is to describe the results of commissioning measurements carried out on the Calypso System to verify the manufacturer specifications and also to evolve a quality assurance (QA) procedure which can be used to test its performance routinely. The QA program consists of a series of tests (QA for checking the calibration or system accuracy, Camera Calibration with L-frame fixture, Camera Calibration with T-frame fixture, System calibration Fixture targets test, Localization, and Tracking). These tests were found to be useful to assess the performance of the Calypso System.

Enhanced thermal transport through a soft glassy nanodisk paste.

We study the diffusion of heat in an aqueous suspension of disk-shaped nanoparticles of Laponite, which has finite elasticity and a pastelike consistency, by using the Mach-Zehnder interferometer. We estimate the thermal diffusivity of the suspension by comparing the experimentally obtained temperature distribution to that with an analytical solution. We observe that, despite the highly constrained Brownian diffusivity of particles owing to its soft glassy nature, suspensions at very small concentrations of Laponite demonstrate significant enhancement in thermal diffusivity. We correlate the observed enhancement with the possible microstructures of the Laponite suspension.

Renal replacement therapy in ICU.

Diagnosing and managing critically ill patients with renal dysfunction is a part of the daily routine of an intensivist. Acute kidney insufficiency substantially contributes to the morbidity and mortality of critically ill patients. Renal replacement therapy (RRT) not only does play a significant role in the treatment of patients with renal failure, acute as well as chronic, but also has spread its domains to the treatment of many other disease conditions such as myaesthenia gravis, septic shock and acute on chronic liver failure. This article briefly outlines the role of renal replacement therapy in ICU.

In vitro and in vivo targeted delivery of photosensitizers to the tumor cells for enhanced photodynamic effects.

BACKGROUND: Efficacy of photodynamic therapy can be enhanced by improving uptake, localization, and sub-cellular localization of sensitizers at the sensitive targets. MATERIALS AND METHODS: Uptake, localization, and photodynamic effects of hematoporphyrin derivative (HpD, Photosan-3; PS-3) and disulfonated aluminum phthalocyanine (AlPcS2) were studied either encapsulated in liposomes or conjugated to a monoclonal antibody to carcinoembryonic antigen (anti-CEA) in a brain glioma cell line, BMG-1. RESULTS: Although the total uptake with encapsulated or conjugated sensitizers was less than the free sensitizers, photodynamic efficiency was higher due to the localization of the sensitizer at the sensitive targets. Biodistribution of intravenously administered technetium (99m Tc)-labeled PS-3 analyzed by gamma camera imaging showed maximum accumulation in the liver followed by tumor. Tumor/muscle (T/N) ratio of free PS-3 was higher compared to encapsulated or conjugated PS-3 but the accumulation of PS-3 significantly reduced in brain and cutaneous tissue following modulated delivery. Pharmacokinetics suggested faster accumulation of encapsulated and conjugated PS-3 in the tumor. CONCLUSION: Localization of sensitizers at sensitive targets and reduced accumulation in normal tissues with liposome encapsulation and antibody conjugation suggest that these two delivery systems can potentially enhance the efficacy of photodynamic treatment.

Assessment of serum IL-1, IL-2 and IFN-γ levels in untreated pulmonary tuberculosis patients: role in pathogenesis.

BACKGROUND AND AIMS: Tuberculosis (Tb) infection is controlled by cell-mediated immunity through mediation of IL-1, IL-2 and IFN-γ. In this study IL-1, IL-2 and IFN-γ were determined in serum samples of untreated pulmonary Tb and control group including apparently healthy individuals or contacts and normal healthy blood donors with an objective of understanding defect(s), if any, in synthesis of any of these cytokines that may lead to a diseased state of Tb. METHODS: IL-1, IL-2 and IFN-γ were measured in serum samples of untreated Tb patients (n=33), contacts (n=19) and healthy individuals (n=20) by commercially available monoclonal antibody-based ELISA. RESULTS: Statistically significant differences in IL-1 and IFN-γ concentrations between groups of pulmonary Tb and controls were observed, whereas no significant difference in IL-2 was seen. CONCLUSIONS: In the present study, increased levels of cytokines in patients with pulmonary Tb are indicative of Th1 response. An increased level of cytokine (IFN-γ) in patients with untreated pulmonary Tb appears to be functionally defective.

A group of low molecular weight (<30 kDa) antigens of heat-killed Mycobacterium tuberculosis H37Rv confer better protection against experimental tuberculosis in guinea pigs.

Heat-killed Mycobacterium tuberculosis (Mtb) H37Rv-derived antigens were purified by electroelution, and their efficacy was evaluated in conferring protection against Tb in guinea pigs in order to identify those protein antigens as a subunit vaccine. A total sonicate extract of Mtb H37Rv (MTSE) was prepared by growing bacteria on Lowenstein-Jensen (LJ) solid medium to its mid-log phase, harvested, and subjected to ultrasonication. Fractions of MTSE were resolved on 10% polyacrylamide gel electrophoresis into as high (HMW, >60 kDa), middle (MMW, 31-59 kDa), and low molecular weight (LMW, <30 kDa) antigens and were purified by electroelution. The protection efficacy of each purified fraction was assessed in a placebo-controlled study by injecting them separately into a group of two animals. After two booster doses, animals were challenged on day 84, and autopsy of all animals was performed on day 126. On autopsy, animals were scored for formation of tubercles in lungs and their dissemination to organs such as spleen, liver, kidney, and lymph nodes. Viable counts (determined as colony forming unit or CFU) of lung and spleen from each animal were performed on LJ solid medium. Results of this study show that CFU of animals that received LMW antigens were significantly low with respect to control animals when compared to MMW and HMW. In conclusion, LMW of Mtb has greater potential in prevention of tubercle formation and thus could be viewed as a possible vaccine candidate in designing alternative subunit vaccines.

Effects of yoga on brain wave coherence in executives.

Aim of this study was to assess the effect of Self Management of Excessive Tension (SMET), a yoga based stress management program on brain wave coherence. Brain wave recordings were taken with Brain Master 2 Channel EEG (version-2.0). The subjects for the study were 72 corporate executives, 48.75 +/- 3.86 years of mean age referred from Oil and Natural Gas Corporation Limited. EEG data was recorded on the first and sixth day of 5 days SMET program. A complete statistical and spectral analysis showed 19.31% increase (p=0.03) in delta, 5.04% increase (p=0.65) in theta, 15.40% increase (p=0.09) in alpha, 1.67% decrease (p=0.54) in beta and 18.68% increase (p=0.07) in gamma wave coherence between pre and post intervention measurements. Taken together, these results suggest that participation in a SMET program was associated with improvement in emotional stability and may have implications for 'Executive Efficiency'. Because before and after designs limit inferences about intervention effects, further research is warranted to explore the effects of SMET program for stress management using a larger, randomized controlled trial.

Influence of colloid infusion on coagulation during off-pump coronary artery bypass grafting.

This study was conducted to determine the influence of colloid infusion on coagulation in patients undergoing off-pump coronary artery bypass grafting (OP-CABG). Thirty patients undergoing elective OP-CABG received medium molecular weight hydroxyethyl starch group I (MMW-HES 200/0.5), low molecular weight hydroxyethyl starch group II (LMW-HES 130/0.4) or gelatin group III (GEL) in a prospective randomized trial. Blood samples were assessed for hemoglobin (Hb), activated coagulation time (ACT), prothrombin time (PT), activated partial thromboplastin time (aPPT), platelet count, fibrinogen and von Willebrand factor (vWF) at specified intervals. Total volume of the colloid infused and postoperative chest-time drainage was also measured. There was a significant decrease in Hb, platelet count, fibrinogen levels in all these groups, which did not warrant blood transfusion. After the colloid infusion, vWF decreased significantly to 67% from baseline in group I as compared to 85 and 79% in group II and group III, respectively. vWF levels remained lower than the baseline value in the first 24 hours in group I, whereas this factor level increased above the baseline values in groups II and III, 6 hours postoperatively. Postoperative chest tube drainage in 24 hours was significantly higher in group I (856 +/- 131 ml) as compared to group II (550 +/- 124 ml) and group III (582 +/- 159 ml). LMW-HES 130/0.4 was superior to MMW-HES 200/0.5 and gelatin in patients undergoing OP-CABG, in terms of better preservation of coagulation associated with enhanced volume effect.

Non-monotonic changes in clonogenic cell survival induced by disulphonated aluminum phthalocyanine photodynamic treatment in a human glioma cell line.

BACKGROUND: Photodynamic therapy (PDT) involves excitation of sensitizer molecules by visible light in the presence of molecular oxygen, thereby generating reactive oxygen species (ROS) through electron/energy transfer processes. The ROS, thus produced can cause damage to both the structure and the function of the cellular constituents resulting in cell death. Our preliminary investigations of dose-response relationships in a human glioma cell line (BMG-1) showed that disulphonated aluminum phthalocyanine (AlPcS2) photodynamically induced loss of cell survival in a concentration dependent manner up to 1 microM, further increases in AlPcS2concentration (>1 microM) were, however, observed to decrease the photodynamic toxicity. Considering the fact that for most photosensitizers only monotonic dose-response (survival) relationships have been reported, this result was unexpected. The present studies were, therefore, undertaken to further investigate the concentration dependent photodynamic effects of AlPcS2. METHODS: Concentration-dependent cellular uptake, sub-cellular localization, proliferation and photodynamic effects of AlPcS2 were investigated in BMG-1 cells by absorbance and fluorescence measurements, image analysis, cell counting and colony forming assays, flow cytometry and micronuclei formation respectively. RESULTS: The cellular uptake as a function of extra-cellular AlPcS2 concentrations was observed to be biphasic. AlPcS2 was distributed throughout the cytoplasm with intense fluorescence in the perinuclear regions at a concentration of 1 microM, while a weak diffuse fluorescence was observed at higher concentrations. A concentration-dependent decrease in cell proliferation with accumulation of cells in G2+M phase was observed after PDT. The response of clonogenic survival after AlPcS2-PDT was non-monotonic with respect to AlPcS2 concentration. CONCLUSIONS: Based on the results we conclude that concentration-dependent changes in physico-chemical properties of sensitizer such as aggregation may influence intracellular transport and localization of photosensitizer. Consequent modifications in the photodynamic induction of lesions and their repair leading to different modes of cell death may contribute to the observed non-linear effects.

Transthoracic electrical bioimpedence cardiac output: comparison with multigated equillibrium radionuclide cardiography.

INTRODUCTION: Thoracic electrical bioimpedance (TEB) for measuring cardiac output (CO) is being explored increasingly as an alternative to pulmonary artery catheter. The major advantage of this technology is that it is non-invasive and easy to perform. Several studies have compared it to thermodilution cardiac output using PA catheter, with variable correlation. Multigated radionuclide equilibrium cardiography (RNEC) method of cardiac output measurement is known to be reliable. OBJECTIVE: To compare cardiac output measured by thoracic electrical bioimpdenace with that measured by multigated radionuclide equilibrium cardiography. PATIENTS AND METHODS: CO studies were performed sequentially at a single sitting by TEB and RNEC methods among patients with cardiac symptoms referred for radionuclide study as part of their evaluation. TEB CO was measured by placing two pairs of electrodes on either side of neck and two other pairs on either side of the lower chest. Stroke volume was estimated from the sequential changes in transthoracic electrical bioimpedance induced by rhythmic aortic blood flow, using Kubicek equation. RNEC-CO was measured by intravenous injection of radio-active Technitium-tagged RBCs followed by ECG gated blood pool imaging over the chest (MUGA study). Bland-Altman analysis was used to compare the measurements. RESULTS: A total of 32 subjects with proven or suspected ischemic heart disease, but without overt cardiac failure, edema or arrhythmias were studied (M:F::26:6; mean age: 48 +/- 12 years). The mean TEB-CO was 3.54 +/- 1.052 l/min and mean RNEC-CO was 3.907 +/- 0.952 l/min. Correlation coefficient (r) for these measurements was 0.67 (p < 0.01), with bias: -0.421 l/min; precision: 1.557 l/min; and percentage error of measurement: 42.35%. CONCLUSIONS: This study observed a moderate correlation between TEB and RNEC methods of CO measurement. Further studies are indicated to explore the relative utility of TEB in comparison with RNEC as well as other methods of CO measurement before considering its use in patients with ischemic heart disease.

Acquisition of equal or better planning results with interstitial brachytherapy when compared with intensity-modulated radiotherapy in tongue cancers.

PURPOSE: Intensity-modulated radiotherapy (IMRT) technique in external beam radiotherapy and interstitial implant brachytherapy (ISBT) play important role in the treatment of head and neck cancers. Both are proved to be highly conformal techniques of radiotherapy. In this study, we investigated whether ISBT can give treatment planning results similar to those of IMRT. METHODS AND MATERIALS: Fifteen patients with tongue cancer treated with interstitial high-dose-rate brachytherapy were replanned. They were evaluated with the IMRT planning system. Contouring of target volume, including all critical structures was done on the IMRT treatment planning system to closely match implant brachytherapy planning system. Treatment plans were generated after specifying the goals in the prescription. Conformity index and dose to critical organ were calculated and compared between IMRT and ISBT. Planning time was also recorded for both the techniques in all the cases. RESULTS: Very good dose conformity was observed in ISBT, which was almost the same as that in IMRT. Dose to the critical structure was lower in ISBT in all the cases. Planner time was also less in ISBT for more number of cases. CONCLUSIONS: Results show that ISBT treatment modality produces equal or superior planning results when compared with IMRT with our optimization techniques. These results encourage us to continue ISBT practice.