Sub-Bandgap Sensitization of Perovskite Semiconductors via Colloidal Quantum Dots Incorporation

By taking advantage of the outstanding intrinsic optoelectronic properties of perovskite-based photovoltaic materials, together with the strong near-infrared (NIR) absorption and electronic confinement in PbS quantum dots (QDs), sub-bandgap photocurrent generation is possible, opening the way for solar cell efficiencies surpassing the classical limits. The present study shows an effective methodology for the inclusion of high densities of colloidal PbS QDs in a MAPbI3 (methylammonium lead iodide) perovskite matrix as a means to enhance the spectral window of photon absorption of the perovskite host film and allow photocurrent production below its bandgap. The QDs were introduced in the perovskite matrix in different sizes and concentrations to study the formation of quantum-confined levels within the host bandgap and the potential formation of a delocalized intermediate mini-band (IB). Pronounced sub-bandgap (in NIR) absorption was optically confirmed with the introduction of QDs in the perovskite. The consequent photocurrent generation was demonstrated via photoconductivity measurements, which indicated IB establishment in the films. Despite verifying the reduced crystallinity of the MAPbI3 matrix with a higher concentration and size of the embedded QDs, the nanostructured films showed pronounced enhancement (above 10-fold) in NIR absorption and consequent photocurrent generation at photon energies below the perovskite bandgap.

"Isolation and characterization of a novel hormone receptor positive mammary adenocarcinoma MCa-P1362 with stromal drivers of tumor growth, metastasis, and drug resistance"

Preclinical models that display spontaneous metastasis are necessary to improve therapeutic options for hormone receptor positive breast cancers. In this study, we conducted a detailed cellular and molecular characterization of MCa-P1362, a novel syngeneic Balb/c mouse model of metastatic breast cancer. MCa-P1362 cancer cells expressed estrogen receptors (ER), progesterone receptors (PR), and HER-2 receptors. MCa-P1362 cells proliferate in vitro and in vivo in response to estrogen, yet do not depend on steroid hormones for tumor progression. Further characterization of MCa-P1362 tumor explants shows that they contain a mixture of epithelial cancer cells and stromal cells. Based on transcriptomic and functional analyses of cancer and stromal cells, stem cells are present in both populations. Functional studies demonstrate that crosstalk between cancer and stromal cells promotes tumor growth, metastasis, and drug resistance. MCa-P1362 may serve as a useful preclinical model to investigate the cellular and molecular basis of hormone receptor positive tumor progression and therapeutic resistance.

Volumetric quantification of choroid and Haller's sublayer using OCT scans: An accurate and unified approach based on stratified smoothing

BACKGROUND AND OBJECTIVE

The choroid, a dense vascular structure in the posterior segment of the eye, maintains the health of the retina by supplying oxygen and nutrients, and assumes clinical significance in screening ocular diseases including age-related macular degeneration (AMD) and central serous chorioretinopathy (CSCR). As a technological assist, algorithmic estimation of choroidal biomarkers has been suggested based on sectional (B-scan) optical coherence tomography (OCT) images. However, most such 2D estimation techniques are compute-intensive, yet enjoy limited accuracy and have only been validated on OCT image datasets of healthy eyes. Not surprisingly, fine-scale analyses, including those involving Haller's sublayer, remain relatively rare and unsophisticated. Against this backdrop, we propose an efficient algorithm to quantify desired biomarkers with improved accuracy based on volume OCT scans. Specifically, we attempted an accurate, computationally light volumetric segmentation method involving stratified smoothing to detect choroid and Haller's sublayer.

METHODS

For detecting the various boundaries of the choroid and the Haller's sublayer, we propose a common volumetric method that performs suitable exponential enhancement and maintains smooth spatial continuity across 2D B-scans. Further, we achieve suitable volumetric smoothing by primarily deploying light-duty linear regression, and sparingly using compute-intensive tensor voting, and hence significantly reduce overall complexity. The proposed methodology is tested on five health and five diseased OCT volumes considering various metrics including volumetric Dice coefficient and corresponding quotient measures to facilitate comparison vis-à-vis intra-observer repeatability.

RESULTS

On five healthy and five diseased OCT volumes, respectively, the proposed method for choroid segmentation recorded volumetric Dice coefficients of 93.53 % and 93.30 %, which closely approximate the respective reference observer repeatability values of 95.60 % and 95.49 %. In terms of related quotient measures, our method achieved more than 50 % improvement over a recently reported method. In detecting Haller's sublayer as well, our algorithm records statistical performance closely matching that of reference manual method.

CONCLUSION

Advancing the state-of-the-art, the proposed volumetric segmentation, tested on both healthy and diseased datasets, demonstrated close match with the manual reference. Our method assumes significance in accurate screening of chorioretinal diseases including AMD, CSCR and pachychoroid. Further, it enables generating accurate training data for developing deep learning models for improved detection of choroid and Haller's sublayer.

Transforming growth factor beta orchestrates PD-L1 enrichment in tumor-derived exosomes and mediates CD8 T-cell dysfunction regulating early phosphorylation of TCR signalome in breast cancer

Tumor cells promote immune evasion through upregulation of programmed death-ligand 1 (PD-L1) that binds with programmed cell death protein 1 (PD1) on cytotoxic T cells and promote dysfunction. Though therapeutic efficacy of anti-PD1 antibody has remarkable effects on different type of cancers it is less effective in breast cancer (BC). Hence, more details understanding of PD-L1-mediated immune evasion is necessary. Here, we report BC cells secrete extracellular vesicles in form of exosomes carry PD-L1 and are highly immunosuppressive. Transforming growth factor beta (TGF-β) present in tumor microenvironment orchestrates BC cell secreted exosomal PD-L1 load. Circulating exosomal PD-L1 content is highly correlated with tumor TGF-β level. The later also found to be significantly associated with CD8+CD39+, CD8+PD1+ T-cell phenotype. Recombinant TGF-β1 dose dependently induces PD-L1 expression in Texos in vitro and blocking of TGF-β dimmed exosomal PD-L1 level. PD-L1 knocked down exosomes failed to suppress effector activity of activated CD8 T cells like tumor exosomes. While understanding its effect on T-cell receptor signaling, we found siPD-L1 exosomes failed to block phosphorylation of src family proteins, linker for activation of T cells and phosphoinositide phospholipase Cγ of CD8 T cells more than PD-L1 exosomes. In vivo inhibition of exosome release and TGF-β synergistically attenuates tumor burden by promoting Granzyme and interferon gamma release in tumor tissue depicting rejuvenation of exhausted T cells. Thus, we establish TGF-β as a promoter of exosomal PD-L1 and unveil a mechanism that tumor cells follow to promote CD8 T-cell dysfunction.

The Multifaceted Effects of Breast Cancer on Tumor-Draining Lymph Nodes

Breast cancer (BC) accounts for significant morbidity and mortality among women worldwide. About one in three patients with breast cancer present with lymph node (LN) metastasis and LN status is one of the most important prognostic predictors in patients with BC. In addition to their prognostic value, LNs initiate adaptive immunity against BC. Yet, BC cells often avoid immune-mediated destruction in LNs. This review provides an overview of the ways by which BC cells modulate LN stromal and hematopoietic cells to promote metastasis and immune evasion.

SOX9: The master regulator of cell fate in breast cancer

SRY-related high-mobility group box 9 (SOX9) is an indispensable transcription factor that regulates multiple developmental pathways related to stemness, differentiation, and progenitor development. Previous studies have demonstrated that the SOX9 protein directs pathways involved in tumor initiation, proliferation, migration, chemoresistance, and stem cell maintenance, thereby regulating tumorigenesis as an oncogene. SOX9 overexpression is a frequent event in breast cancer (BC) subtypes. Of note, the molecular mechanisms and functional regulation underlying SOX9 upregulation during BC progression are still being uncovered. The focus of this review is to appraise recent advances regarding the involvement of SOX9 in BC pathogenesis. First, we provide a general overview of SOX9 structure and function, as well as its involvement in various kinds of cancer. Next, we discuss pathways of SOX9 regulation, particularly its miRNA-mediated regulation, in BC. Finally, we describe the involvement of SOX9 in BC pathogenesis via its regulation of pathways involved in regulating cancer hallmarks, as well as its clinical and therapeutic importance. In general, this review article aims to serve as an ample source of knowledge on the involvement of SOX9 in BC progression. Targeting SOX9 activity may improve therapeutic strategies to treat BC, but precisely inhibiting SOX9 using drugs and/or small peptides remains a huge challenge for forthcoming cancer research.

MicroRNA-222 reprogrammed cancer-associated fibroblasts enhance growth and metastasis of breast cancer

BACKGROUND

Cancer-associated fibroblasts (CAFs) are known to impact on tumour behaviour, but the mechanisms controlling this are poorly understood.

METHODS

Breast normal fibroblasts (NFs) or CAFs were isolated from cancers by laser microdissection or were cultured. Fibroblasts were transfected to manipulate miR-222 or Lamin B receptor (LBR). The fibroblast-conditioned medium was collected and used to treat epithelial BC lines MDA-MB-231 and MDA-MB-157. Migration, invasion, proliferation or senescence was assessed using transwell, MTT or X-gal assays, respectively.

RESULTS

MiR-222 was upregulated in CAFs as compared with NFs. Ectopic miR-222 expression in NFs induced CAF-like expression profiles, while miR-222 knockdown in CAFs inhibited CAF phenotypes. LBR was identified as a direct miR-222 target, and was functionally relevant since LBR knockdown phenocopied miR-222 overexpression and LBR overexpression phenocopied miR-222 knockdown. MiR-222 overexpression, or LBR knockdown, was sufficient to induce NFs to show the CAF characteristics of enhanced migration, invasion and senescence, and furthermore, the conditioned medium from these fibroblasts induced increased BC cell migration and invasion. The reverse manipulations in CAFs inhibited these behaviours in fibroblasts, and inhibited paracrine influences on BC cells.

CONCLUSION

MiR-222/LBR have key roles in controlling pro-progression influences of CAFs in BC. This pathway may present therapeutic opportunities to inhibit CAF-induced cancer progression.

The role of polymers in cross-kingdom bioadhesion

The secretion of extracellular polymeric substances provides an evolutionary advantage found in many organisms that can adhere to surfaces and cover themselves in a protective matrix. This ability is found in prokaryotes, archaea and eukaryotes, all of which use functionally similar polysaccharides, proteins and nucleic acids to form extracellular matrices, mucus and bioadhesive substances. These macromolecules have been investigated from the perspective of polymer biophysics, and theories to help understand adhesion, viscosity and gelling have been developed. These properties can be measured experimentally using straightforward methods such as cell counting as well as more advanced techniques such as atomic force microscopy and rheometry. An integrated understanding of the properties and uses of adhesive macromolecules across kingdoms is also important and can provide the basis for a range of biotechnological and medical applications. This article is part of the theme issue 'Transdisciplinary approaches to the study of adhesion and adhesives in biological systems'.

Infrared tunable, two colour-band photodetectors on flexible platforms using 0D/2D PbS-MoS2 hybrids

Two-dimensional (2D) MoS₂ nanosheets have been integrated with zero-dimensional (0D) PbS quantum dots to achieve a superior optical response extending to the short-wavelength infrared region along with a broadband visible response for multispectral photodetection. The 0D/2D hybrid nanostructures have been synthesized by a one pot, stabilizer-free solvothermal growth process. Microscopic and spectroscopic studies confirmed the formation of PbS QD decorated semiconducting 2H-MoS₂ layers. The size tunable absorption features with longer photo-generated carrier lifetime of synthesized hybrid nanostructures indicate that the integration of PbS QDs in MoS₂ could be a viable approach for fabricating two-colour band photodetectors, viz. visible broadband and wavelength selective short-wave IR photodetectors. Devices have also been demonstrated on polyethylene terephthalate substrates using a solution-based synthesis technique for flexible and ultrathin optoelectronic device applications. The photodetection performance of fabricated devices suggests that the synergic 0D/2D hybrid nanostructures are significantly superior to solution processed hybrid devices operating in the infrared region. The successful integration of 0D QDs in 2D materials may pave the way for novel, high performance, next-generation CMOS compatible flexible photonic devices.

Notch signaling in breast cancer: From pathway analysis to therapy

The Notch signaling pathway, which is highly conserved from sea urchins to humans, plays an important role in cell-differentiation, survival, proliferation, stem-cell renewal, and determining cell fate during development and morphogenesis. It is well established that signaling pathways are dysregulated in a wide-range of diseases, including human malignancies. Studies suggest that the dysregulation of the Notch pathway contributes to carcinogenesis, cancer stem cell renewal, angiogenesis, and chemo-resistance. Elevated levels of Notch receptors and ligands have been associated with cancer-progression and poor survival. Furthermore, the Notch signaling pathway regulates the transcriptional activity of key target genes through crosstalk with several other signaling pathways. Indeed, increasing evidence suggests that the Notch signaling pathway may serve as a therapeutic target for the treatment of several cancers, including breast cancer. Researchers have demonstrated the anti-tumor properties of Notch inhibitors in various cancer types. Currently, Notch inhibitors are being evaluated for anticancer efficacy in a number of clinical-trials. However, because there are multiple Notch receptors that can exhibit either oncogenic or tumor-suppressing roles in various cells, it is important that the Notch inhibitors are specific to particular receptors that are tumorigenic in nature. This review critically evaluates existing Notch inhibitory drugs and strategies and summarizes the previous discoveries, current understandings, and recent developments in support of Notch receptors as therapeutic targets in breast cancer.

Robust Heartbeat Detection From Multimodal Data via CNN-Based Generalizable Information Fusion

OBJECTIVE

Heartbeat detection remains central to cardiac disease diagnosis and management, and is traditionally performed based on electrocardiogram (ECG). To improve robustness and accuracy of detection, especially, in certain critical-care scenarios, the use of additional physiological signals such as arterial blood pressure (BP) has recently been suggested. Therefore, estimation of heartbeat location requires information fusion from multiple signals. However, reported efforts in this direction often obtain multimodal estimates somewhat indirectly, by voting among separately obtained signal-specific intermediate estimates. In contrast, we propose to directly fuse information from multiple signals without requiring intermediate estimates, and thence estimate heartbeat location in a robust manner.

METHOD

We propose as a heartbeat detector, a convolutional neural network (CNN) that learns fused features from multiple physiological signals. This method eliminates the need for hand-picked signal-specific features and ad hoc fusion schemes. Furthermore, being data-driven, the same algorithm learns suitable features from arbitrary set of signals.

RESULTS

Using ECG and BP signals of PhysioNet 2014 Challenge database, we obtained a score of 94%. Furthermore, using two ECG channels of MIT-BIH arrhythmia database, we scored 99.92%. Both those scores compare favorably with previously reported database-specific results. Also, our detector achieved high accuracy in a variety of clinical conditions.

CONCLUSION

The proposed CNN-based information fusion (CIF) algorithm is generalizable, robust and efficient in detecting heartbeat location from multiple signals.

SIGNIFICANCE

In medical signal monitoring systems, our technique would accurately estimate heartbeat locations even when only a subset of channels are reliable.

A setup for element specific magnetization dynamics using the transverse magneto-optic Kerr effect in the energy range of 30-72 eV

In this paper, we present a spectrometer that is designed for element-specific and time-resolved transverse magneto-optic Kerr effect experiments at the high-harmonic generation pump-probe facility High Energy Laser Induced Overtone Source (HELIOS) laboratory. HELIOS delivers photons with energies between 30 eV and 72 eV with an overall time resolution of less than 40 fs. The spectrometer is based on a Rowland-circle geometry and allows for simultaneous measurements of all magnetic transition-metal elements. The setup also features easy sample transfer and alignment, and it combines high photon throughput, optimized data acquisition, and a fast switching of the magnetic field at the sample. The spectrometer performance is demonstrated by measuring the ultrafast demagnetization of permalloy. Our data are, for all practical purposes, identical to what have been reported in the earlier high-order harmonic generation work of a similar sample by Mathias et al. [Proc. Natl. Acad. Sci. U. S. A. 109, 4792-4797 (2012)], however, obtained within 15% of the acquisition time compared to their study. Furthermore, our data show a shift of the demagnetization curve of Ni relative to Fe, which has previously been interpreted as a delay of the Ni demagnetization to that of Fe [S. Mathias et al., Proc. Natl. Acad. Sci. U. S. A. 109, 4792-4797 (2012)].

miR-216b suppresses breast cancer growth and metastasis by targeting SDCBP

Breast cancer is the most deadly cancer among women and the second leading cause of cancer death worldwide. Treatment effectiveness is complicated with tumor invasiveness/drug resistance. To tailor treatments more effectively to individual patients, it is important to define tumor growth and metastasis at molecular levels. SDCBP is highly overexpressed and associated with a strikingly poor prognosis in breast cancer. However the post transcriptional regulation of SDCBP overexpression remains to be an unexplored area. Our study reveals that miR-216b directly regulates SDCBP expression by binding to its 3'UTR region. miR-216b is a tumor suppressive miRNA and it is underexpressed during metastatic breast cancer. Consequently, overexpression of miR-216b resulted in decreased proliferation, migration and invasion in BC cell lines by modulating the expression of SDCBP. Inhibition of miR-216b divergent the tumor suppressive role by inducing the growth proliferation, migration and invasion in vitro. There is therefore a negative correlation between the expression of miR-216b and its target gene SDCBP in the BC tissue samples as well as cell lines. Simultaneous expression of miR-216b and SDCBP rescued the growth, migration and invasion effect suggesting that tumor suppressive action of miR-216b may be directly mediated by SDCBP. In summary, the study identifies miR-216b as a regulator of SDCBP expression in breast cancer which can potentially be targeted for developing newer therapies for the effective treatment of this killer disease.

Detection and characterization of zoonotic dermatophytes from dogs and cats in and around Kolkata

Aim:

The ringworms of pet dogs, cats, and stray animals (dogs, cats, and other animals) could be a potential source of zoonotic infections causing a serious public health problem in the busy city Kolkata. The pet owners are more susceptible to get this infection from their pets, because of the close contact with them as dermatophytosis is very much prevalent in those pets. So, this study was aimed to check the prevalence of dermatophytosis in dogs, cats, and in pet owners.

Materials and Methods:

A total of 362 clinically suspected cases of dermatophytosis from dogs (123 in number), cats (202 in number), and human beings (37 in number) were collected and studied from in and around Kolkata to detect the presence of significant dermatophytes. Direct microscopy and cultural examination of the isolates were performed following standard methodology. Identification and characterization of the isolates were done by different biochemical tests.

Results:

Samples (n=285) having significant dermatophytic fungal infections were found to be of highest number in cats (158, 55.5%) than in dogs (108, 37.8%) and humans (19, 6.7%), respectively. The incidence of Microsporum canis (60.0%) was the highest from affecting dogs, cats, and human beings in comparison to Microsporum gypseum (22.5%), Trichophyton mentagrophytes (15.8%) and Trichophyton rubrum (1.7%). Detection of T. rubrum was only from human cases in this study, whereas the presence of rest three were slightly higher in cats than that of the dogs and humans in this present study. The incidences were higher in young animals and in humans of the age group of 21-30 years, during the rainy season (from April to August) and also in in-contact human beings.

Conclusion:

M. canis was the most commonly pathogen among all causing dermatophytosis in animals and also in the pet owners. M. gypseum and T. mentagrophytes were other pathogens associated with these infections. These infections were more prevalent in the rainy seasons and in in-contact human patients or pet owners.

Lupus cystitis: An unusual presentation of systemic lupus erythematosus

Lupus cystitis is a rare complication of systemic lupus erythematosus (SLE) and occurs in association with gastrointestinal symptoms. This rare disorder has been reported mainly from Japan. We report a 20 year old female who diagnosed as having SLE associated with paralytic ileus and chronic interstitial cystitis. Treatment with intravenous methylprednisolone, cyclophosphamide pulse therapy followed by oral prednisolone and azathioprine led to amelioration of manifestations. Later she developed lupus nephritis which was treated with mycophenolate mofetil.

Scaffolds for tissue engineering of cardiac valves

Tissue engineered heart valves offer a promising alternative for the replacement of diseased heart valves avoiding the limitations faced with currently available bioprosthetic and mechanical heart valves. In the paradigm of tissue engineering, a three-dimensional platform - the so-called scaffold - is essential for cell proliferation, growth and differentiation, as well as the ultimate generation of a functional tissue. A foundation for success in heart valve tissue engineering is a recapitulation of the complex design and diverse mechanical properties of a native valve. This article reviews technological details of the scaffolds that have been applied to date in heart valve tissue engineering research.

Macro-anatomical variation of the olfactory apparatus in some Indian teleosts with special reference to their ecological habitat

The anatomy of the peripheral olfactory apparatus (i.e. olfactory lamellae, olfactorychambers, accessory nasal sacs, olfactory nerve tracts, olfactory bulbs and brain) of some teleosts, viz. Pseudapocryptes lanceolatus (Bloch and Schneider, 1801) - an air breathing mudskipper, Lepidocephalichthys guntea (Hamilton, 1822) - a freshwater scavenger fish and Mastacembelus armatus (Lacepède, 1800) - a freshwater potamodromous fish, has been studied in relation to their specific ecological habitat. Live, adult, sex-independent fish species were collected from the local markets of West Bengal, India, and acclimatised with the laboratory conditions (for 72 h at 32°C). The specimens were anaesthetised by MS-222 (dose: 100-200 mg/L). Olfactory apparatuses were dissected out and fixed inaqueous Bouin's solution. The macro- and microstructures (using haematoxylin and eosin) of the olfactory apparatuses were examined under binocular light microscope (LM) and trinocular LM (Primo Star; Carl Zeiss Microscpy, GmbH, Germany) respectively. P. lanceolatus possesses unilamellar olfactory apparatus at therounded snout, whereas L. guntea shows small rosette with 18 to 24 lamellae oneither side of the elliptical snout. Elongated olfactory rosette (number of lamellae ranges from 60 to 76) is present at the pointed snout of M. armatus. Morpho-anatomical variation in snout structure of the respective species is an indicative of divergence in ecological habitat, but variation in olfactory apparatus is significant for species-specific differentiation. Pseudostratified olfactory neuroepithelial components (i.e. sensory receptor cell, supporting cell and basal cell) show striking similarities amongst these species. Therefore comparative anatomical changes of the snout and olfactory apparatus are not only representing ecological habitat based on interspecific variation, but may also indicate the phylogenetic relation amongst said species.

Automated detection of choroid boundary and vessels in optical coherence tomography images

Structural changes in the choroid, a layer located between the retina and sclera, could indicate various vision impairments. Consequently, ophthalmologists inspect optical coherence tomography (OCT) scans of the posterior section of the eye towards making diagnosis. With a view to assist diagnosis, we propose an automated technique for segmentation of the choroid layer. Specifically, we detect the upper and lower boundaries of the choroid using structural similarity and adaptive Hessian analysis. Subsequently, we detect choroid vessels within those boundaries using a level set method. Experimental results are presented using spectral domain (SD) OCT images.

Immunodiagnosis as an aid for early detection of Fasciola gigantica by glutathione S-transferase (GST)

In the present study, effort to isolate purified GST from Fasciola gigantica homogenate and its early detection for confirmation of infection has been successful. In this study, immunoprotection studies with GST and antibody titer post-infection has revealed GST to be an immunogenic protein with high sensitivity to detect anti-Fasciola antibody as early as two weeks post-infection in large ruminants.

Cooperative involvement of NFAT and SnoN mediates transforming growth factor-β (TGF-β) induced EMT in metastatic breast cancer (MDA-MB 231) cells

Epithelial to mesenchymal transition (EMT) is a secondary phenomenon concomitantly associated with the tumor progression. The regulatory signals and mechanistic details of EMT are not fully elucidated. Here, we shared a TGF-β mediated mechanism of EMT in breast cancer (MDA-MB 231) cells. Initial exposure of TGF-β for 48 h, enhanced the rate of cell proliferation and associated with EMT of MDA-MB 231 cells. The EMT was characterized by observing the increased N-cadherin, fibronectin, Snail expression and associated with the morphological change with a reduced E-cadherin expression. NFAT, a transcription factor, alters tumor suppressive function of TGF-β towards tumor progression. Up regulation of NFAT, coupled with a foremost translocation of one oncogenic protein SnoN from cytoplasm to nucleus was noticed during this TGF-β mediated EMT. Silencing of NFAT also showed the inhibition of TGF-β mediated EMT characterized by down regulation of N-cadherin and associated with reduced expression of SnoN. In addition, it was also observed that NFAT sequestering the Smad3 prevents the proteasome mediated degradation of SnoN and this SnoN has a role on the regulation of MMP-2, MMP-9 activity. Increased Smad3-SnoN interaction and proteasome mediated degradation of SnoN were detected after silencing of NFAT with a reduced MMP-2, MMP-9 activity. All of these observations provide a fresh mechanism in which by a twofold involvement of NFAT and SnoN plays a crucial role in TGF-β mediated EMT by recruiting the effector molecules N-cadherin and MMP-2, MMP-9.

Wetting and surface energy of vertically aligned silicon nanowires

The vertically aligned silicon nanowires (SiNWs) have been synthesized by metal assisted chemical etching process on commercially available p type silicon wafer. The aspect ratios of the SiNWs have been modified by simply varying the etching time. The microstructures of the as prepared samples have been investigated with the field emission scanning electron microscope as well as with a high resolution transmission electron microscope. The bonding information has been obtained by Fourier transformed infrared spectroscopy and X-ray photoelectron spectroscopy. The contact angles for water with the as-prepared SiNWs films were measured and found to be highly dependent upon the aspect ratio of the as synthesized wires. For obtaining a deep insight regarding the reasons behind this dependence the surface energies of the as prepared SiNWs films have been calculated by Owens method using two liquids, water and glycerol. The porosity of the films has been calculated indirectly from the equilibrium equations. It has been found that the etching time has a profound effect on the aspect ratio and thus on the surface energy of SiNWs that governs the wetting behaviour of the as prepared samples.

An agglomeration induced glassy magnetic state in a carbon nanotube/NiO nanocomposite system

A series of nanocomposite materials were synthesized using multi-walled carbon nanotubes (MWCNTs) and NiO nanoparticles by varying the concentration of NiO in the MWCNT host matrix. Such an increment in the NiO particle density actually tunes the degree of isolation among the magnetic nanoparticles. Careful investigation by transmission electron microscopy shows that particle agglomeration increases substantially with NiO particle density. Field dependence of magnetization measurements depict a gradual enhancement of coercivity with increasing NiO concentration, signifying the enhancement of magnetic anisotropy in this nanocomposite system. Furthermore, field cooled and zero field cooled memory effect as well as magnetization relaxation measurements show that a glassy magnetic state gradually develops when the concentration increases. Analysis based on the result of high resolution transmission electron microscopy along with the magnetization data reveals that interparticle magnetic exchange interaction in the presence of interfacial disorders plays the major role in the emergence of the glassy magnetic state in this nanocomposite system.

Synthesis of Some New Isoxazoline Derivatives of Chalconised Indoline 2-one as a Potential Analgesic, Antibacterial and Anthelmimtic Agents

A series of novel 1[5”-(2”’-substituted phenyl)-4”,5”’-dihydro isoxazole-3”-yl]-3-[(4 substituted phenyl)imino]1-3-dihydro-2H-indole-2-one were synthesized from different substituted chalconised indole-2,3-dione was prepared from the different chalconised Isatin. The structures of the compounds were elucidated by elemental and spectral (IR, ¹H NMR, and MS) analysis. The synthesized compounds were screened for their analgesic activity by the acetic acid induced Writhing method and in vitro antimicrobial activity against the Gram-positive bacteria—Staphylococcus aureus and the Gram-negative bacteria—Pseudomonas auroginosa, Pseudomonas mirabilis, and E. coli by the cup plate agar diffusion method. Compounds 6a₁, 6a₃, 6b₃, and 6b₂ were found to be active against bacteria. The compounds 6a₁, 6b₃, and 6a₃ show a significant analgesic activity. Synthesized compounds also screened for anthelmintic activity against Pheretima posthuma. Compounds 6a₁, 6b₁, and 6b₃ show significant anthelmintic activity.

Anethum graveolens: An Indian traditional medicinal herb and spice

Anethum graveolens L. (dill) has been used in ayurvedic medicines since ancient times and it is a popular herb widely used as a spice and also yields essential oil. It is an aromatic and annual herb of apiaceae family. The Ayurvedic uses of dill seeds are carminative, stomachic and diuretic. There are various volatile components of dill seeds and herb; carvone being the predominant odorant of dill seed and α-phellandrene, limonene, dill ether, myristicin are the most important odorants of dill herb. Other compounds isolated from seeds are coumarins, flavonoids, phenolic acids and steroids. The main purpose of this review is to understand the significance of Anethum graveolens in ayurvedic medicines and non-medicinal purposes and emphasis can also be given to the enhancement of secondary metabolites of this medicinal plant.

Prodrug design to improve pharmacokinetic and drug delivery properties: challenges to the discovery scientists

The prodrug design is a versatile, powerful method that can be applied to a wide range of parent drug molecules, administration routes, and formulations. Clinically, the majority of prodrugs are used with the aim of enhancing drug permeation by increasing lipophilicity, or by improving aqueous solubility. Prodrug design may improve the bioavailability of parent molecule, and thus can be integrated into the iterative process of lead optimization, rather than employing it as a post-hoc approach. The purpose of this review is to provide an update of advances and progress in the knowledge of current strategic approaches of prodrug design, along with their real-world utility in drug discovery and development. The review covers the type of prodrugs and functional groups that are amenable to prodrug design. Various prodrug approaches for improving oral drug delivery are discussed, with numerous examples of marketed prodrugs, including improved aqueous solubility, improved lipophilicity, transporter-mediated absorption, and prodrug design to achieve site-specific delivery. Tools employed for prodrug screening, and specific challenges in prodrug research and development are also elaborated. This article is intended to encourage discovery scientists to be creative and consider a rationally designed prodrug approach during the lead optimization phase of drug discovery programs, when the structure activity relationship (SAR) for the drug target is incompatible with pharmacokinetic or biopharmaceutical objectives.

Synthesis and evaluation of 1,3 di-substituted schiff, mannich bases and spiro isatin derivatives

Schiff bases of isatin with aminothiazole, its N-mannich bases and Spiro isatin derivatives were synthesized. Their chemical structures were confirmed by Infrared, 1H-Nuclear Magnetic Resonance data and elemental analysis. Antimicrobial evaluation was performed by the agar diffusion method against four pathogenic bacteria and two pathogenic fungi. Anti-inflammatory activity was tested by carragenin-induced rat paw edema and compounds were evaluated for analgesic action by the acetic acid-induced writhing method; Compounds Aa, Ab and A5, A6 were found to be active against bacteria and fungi. The compounds A3, A6, Aa and Ab showed anti-inflammatory activity, having a percentage protection value of 34.69, 32.65, 38.77 and 36.73 as compared with that of indomethacin, with % protection of 46.93. Similarly, the compounds Aa, Ab and A6 showed analgesic activity, with % protection of 67.51, 64.78 and 49.81 as compared with the standard with % protection of 79.56.

Dynamic changes in CD4+ CD25+(high) T cell apoptosis after the diagnosis of type 1 diabetes

Because type 1 diabetes (T1D) is a chronic, autoimmune, T cell-mediated disease, interventions affecting T cells are expected to modulate the immune cascade and lead to disease remission. We propose that increased CD4(+) CD25(+high) T cell apoptosis, a trait we discovered in recent-onset T1D subjects, reflects T1D partial remission within the first 6 months after diagnosis. Apoptosis of forkhead box P3 (FoxP3)(+) CD4(+) CD25(+high) T cells, in addition to total daily doses of insulin (TDD), blood glucose, HbA1c and age, were measured in 45 subjects with T1D at various times after diagnosis. Sixteen healthy control subjects were also recruited to the study. Higher CD4(+) CD25(+high) T cell apoptosis levels were detected within the first 6 months of diagnosis (odds ratio = 1.39, P = 0.009), after adjustment for age, TDD and HbA1c. A proportional hazards model confirmed that the decline of apoptosis after diagnosis of T1D was related significantly to survival time (hazards ratio = 1.08, P = 0.014), with TDD and age also contributing to survival. During this time there was an inverse relationship between CD4(+) CD25(+high) T cell apoptosis with TDD (r = -0.39, P = 0.008). The CD4(+) CD25(+high) T cell apoptosis levels decline significantly after the first 6 months from diagnosis of T1D and may help in the close monitoring of autoimmunity. In parallel, there is an increase in TDD during this time. We also propose that CD4(+) CD25(+high) T cell apoptosis assay can be used to gauge the efficacy of the several immune tolerance induction protocols, now under way.