Improved Surface-Enhanced Raman Scattering Performance of 2D Ti3C2Tx MXene Embedded in PVDF Film Enabled by Photoinduction and Electric Field Modulation.

In this study, we introduce a synergistic approach to enhance the surface-enhanced Raman scattering (SERS) signal in two-dimensional (2D) MXene through photo-irradiation and electric field modulation. Our methodology involves the integration of 2D Ti3C2Tx MXene with piezoelectric polyvinylidene fluoride (PVDF) polymer, resulting in the creation of a free-standing, flexible composite film. On this composite film, a thin layer of Au was deposited. Our flexible substrate was able to sense methylene blue (MB), crystal violet (CV), 4-aminothiophenol (ATP), and melamine. The SERS substrate exhibits low detection limit of 10-8 M MB with a 6.7 × 106 enhancement factor (EF). The SERS substrate enables picomolar (pM) detection sensitivity for CV molecules with an EF of 9.2 × 109. Furthermore, the introduction of photo-irradiation leads to an additional ∼3.5-fold enhancement in the SERS signal, which is attributed to the altered work function and defects. The application of mechanical force to the piezoelectric PVDF/Ti3C2Tx film results in a ∼4.5-fold boost in SERS signal due to mechanical force-induced electrical energy. The fabrication strategy employed here for producing a flexible piezoelectric PVDF/Ti3C2Tx film holds significant promise for expanding the potential application of 2D MXene in rapid, on-site sensing scenarios.

Assessment of Serum Parameters in Stable Coronary Artery Disease Patients in Correlation with Healthy and Chronic Periodontitis Patients.

Background: Periodontitis is a chronic inflammatory disease and has been strongly associated with elevation of systemic markers such as C-reactive protein (CRP), fibrinogen (FIB), and lipid profile, which have also been significantly associated with coronary heart disease (CHD). Hence, there is a need to assess the possible association between chronic periodontitis and coronary artery disease. Materials and Methods: A study included 100 subjects divided into four groups. Group I: stable coronary artery disease with chronic periodontitis, Group II: stable coronary artery disease without chronic periodontitis, Group III: chronic periodontitis without coronary artery disease, and Group IV: healthy controls. Gingival index, Russell's periodontal index, pocket depth, and clinical attachment level were recorded. Venous blood was collected from the patients, and serum fibrinogen, CRP, and lipid profile levels were estimated. Results: The intragroup comparison of biochemical and periodontal parameters showed statistically significant results with P < 0.05. The intergroup comparison of serum FIB, total cholesterol, high density lipoprotein, low density lipoprotein, and clinical attachment level showed statistical significant results (P = 0.000, P = 0.000, P = 0.001, P = 0.025, and P = 0.000, respectively) between Groups I and III. Conclusion: The results of the study indicate that there might a possible correlation between coronary artery disease and chronic periodontitis, but periodontitis-cardiovascular link is complex and difficult to define though there is sufficient evidence for their association. Leakage of pro-inflammatory cytokines from the ulcerated periodontium causes the production of acute-phase proteins by the liver. To prove the relationship, further studies should be considered making use of other markers of inflammation with prospective randomized controlled studies involving large population.

Functionalization and patterning of nanocellulose films by surface-bound nanoparticles of hydrolyzable tannins and multivalent metal ions.

Inspired by the Bogolanfini dyeing technique, we report how flexible nanofibrillated cellulose (CNF) films can be functionalized and patterned by surface-bound nanoparticles of hydrolyzable tannins and multivalent metal ions with tunable colors. Molecular dynamics simulations show that gallic acid (GA) and ellagic acid (EA) rapidly adsorb and assemble on the CNF surface, and atomic force microscopy confirms that nanosized GA assemblies cover the surface of the CNF. CNF films were patterned with tannin-metal ion nanoparticles by an in-fibre reaction between the pre-impregnated tannin and the metal ions in the printing ink. Spectroscopic studies show that the FeIII/II ions interact with GA and form surface-bound, stable GA-FeIII/II nanoparticles. The functionalization and patterning of CNF films with metal ion-hydrolyzable tannin nanoparticles is a versatile route to functionalize films based on renewable materials and of interest for biomedical and environmental applications.

Classification systems for gingival recession and suggestion of a new classification system.

BACKGROUND: Gingival recession is one of the most usual esthetic concerns associated with the periodontal tissues. Classification of such condition is important to diagnose, determine the prognosis, and frame the treatment plan. Various classifications have been put forward since decades to classify gingival recession. Miller's classification is the widely used classification among all classifications, but certain drawbacks have been noted in this classification. Therefore, an effort is made to review most commonly used classification systems for gingival recession, and their drawbacks further come up with a proposal of new classification system for gingival recession.

Non-cirrhotic portal fibrosis at a tertiary care centre in South India.

BACKGROUND: Non-cirrhotic portal fibrosis (NCPF) is one of the important causes of upper gastrointestinal haemorrhage in patients in tropical countries. The aim of this study was to describe the clinical and laboratory profile of 68 patients with NCPF. MATERIAL AND METHODS: NCPF is defined as liver disease with: (1) evidence of portal hypertension; (2) a liver biopsy showing no cirrhosis or a Tc-labelled sulphur colloid scan showing a pattern suggestive of NCPF; and (3) a patent splenoportal axis. The clinical, laboratory and demographic features of 68 patients with such criteria were studied and analysed. RESULTS: NCPF was common in women (73.5%) in the fourth decade of life. The median duration of illness was 24 months (range, 1 month-28 years). Patients presented to hospital with the sensation of a mass in the abdomen (50%) or with haematemesis (26.5%). They had splenomegaly (95.6%) and thrombocytopenia (88.2%). The majority of patients had normal liver function tests. Abdominal ultrasonography showed increased periportal and peri gallbladder echoes (72%), spontaneous collaterals (41.2%) and ascites (19.1%). Liver biopsy revealed portal venous sclerosis (76.3%) and periportal fibrosis (55.3%). Tc-labelled sulphur colloid scan was suggestive of NCPF in the remaining 30 cases. CONCLUSION: NCPF is common in South India. Transient ascites occurs due to decompensation of liver function after variceal bleeding and in long standing cases of NCPF. Our study used Tc-sulphur scan for diagnosing NCPF in patients where liver biopsy was contraindicated in view of severe thrombocytopenia; however, the diagnostic utility of Tc-sulphur nuclear scan to diagnose NCPF in patients with severe hypersplenism needs to be further evaluated in future studies.

Visualizing chemical states and defects induced magnetism of graphene oxide by spatially-resolved-X-ray microscopy and spectroscopy.

This investigation studies the various magnetic behaviors of graphene oxide (GO) and reduced graphene oxides (rGOs) and elucidates the relationship between the chemical states that involve defects therein and their magnetic behaviors in GO sheets. Magnetic hysteresis loop reveals that the GO is ferromagnetic whereas photo-thermal moderately reduced graphene oxide (M-rGO) and heavily reduced graphene oxide (H-rGO) gradually become paramagnetic behavior at room temperature. Scanning transmission X-ray microscopy and corresponding X-ray absorption near-edge structure spectroscopy were utilized to investigate thoroughly the variation of the C 2p(π*) states that are bound with oxygen-containing and hydroxyl groups, as well as the C 2p(σ*)-derived states in flat and wrinkle regions to clarify the relationship between the spatially-resolved chemical states and the magnetism of GO, M-rGO and H-rGO. The results of X-ray magnetic circular dichroism further support the finding that C 2p(σ*)-derived states are the main origin of the magnetism of GO. Based on experimental results and first-principles calculations, the variation in magnetic behavior from GO to M-rGO and to H-rGO is interpreted, and the origin of ferromagnetism is identified as the C 2p(σ*)-derived states that involve defects/vacancies rather than the C 2p(π*) states that are bound with oxygen-containing and hydroxyl groups on GO sheets.

Understanding of sub-band gap absorption of femtosecond-laser sulfur hyperdoped silicon using synchrotron-based techniques.

The correlation between sub-band gap absorption and the chemical states and electronic and atomic structures of S-hyperdoped Si have been extensively studied, using synchrotron-based x-ray photoelectron spectroscopy (XPS), x-ray absorption near-edge spectroscopy (XANES), extended x-ray absorption fine structure (EXAFS), valence-band photoemission spectroscopy (VB-PES) and first-principles calculation. S 2p XPS spectra reveal that the S-hyperdoped Si with the greatest (~87%) sub-band gap absorption contains the highest concentration of S(2-) (monosulfide) species. Annealing S-hyperdoped Si reduces the sub-band gap absorptance and the concentration of S(2-) species, but significantly increases the concentration of larger S clusters [polysulfides (Sn(2-), n > 2)]. The Si K-edge XANES spectra show that S hyperdoping in Si increases (decreased) the occupied (unoccupied) electronic density of states at/above the conduction-band-minimum. VB-PES spectra evidently reveal that the S-dopants not only form an impurity band deep within the band gap, giving rise to the sub-band gap absorption, but also cause the insulator-to-metal transition in S-hyperdoped Si samples. Based on the experimental results and the calculations by density functional theory, the chemical state of the S species and the formation of the S-dopant states in the band gap of Si are critical in determining the sub-band gap absorptance of hyperdoped Si samples.

Allele and genotype frequency of a genetic variant in ataxia telangiectasia mutated gene affecting glycemic response to metformin in South Indian population.

UNLABELLED: Allele and genotype frequency of a genetic variant in ATM gene affecting glycemic response to metformin in South Indian population. CONTEXT: The novel polymorphism in ATM gene (rs11212617), which is implicated to have association with metformin response, exhibits inter-ethnic variability in the allele and genotype frequency distribution. AIMS AND DESIGN: The objective of the present study is to establish the allele and genotype frequency of rs11212617 single nucleotide polymorphism in ATM gene, in South Indian population and to find if this variant has any role in the etiology of type 2 diabetes mellitus. MATERIALS AND METHODS: The study was performed in 2 cohorts of populations, 112 healthy volunteers and 118 type 2 diabetes mellitus patients. Genomic deoxyribonucleic acid (DNA) was extracted from peripheral blood leucocytes by phenol-chloroform method and genotyping was performed by real-time polymerase chain reaction using TaqMan assay. RESULTS: In South Indian population, the frequency of major A allele was 0.65 and the minor C allele was 0.35. AA and CC are the homozygous genotypes with frequency of 0.39 and 0.09 respectively. The frequency of heterozygous genotype AC (0.52) was found to be higher than the homozygotes. There was no significant difference in the frequency distribution in the diabetic population, which implies that this variant does not have any causative role in the disease etiology. The frequency distributions were found to be significantly different from the distributions in other ethnic populations such as Caucasians, Chinese, Japanese and Africans. But there was no significant difference when compared with the Gujarati Indians of Houston. CONCLUSION: The frequency distribution of this novel variant in South Indian population forms a framework for further gene disease association studies to establish the association of this variant with metformin response. Our study could not find any association of this variant with respect to the disease etiology.

Multicentric, Hyaline Vascular Variant of Castleman's Syndrome.

Castleman's disease is a nonneoplastic adenopathy, also known as angiofollicular or giant lymphnode hyperplasia. Its multicentric form presents with wide spread lymphadenopathy and systemic symptoms. POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, skin changes) is observed in 11-30 % of the patients with Castleman's disease (Dispenzieri et al., Blood 101:2496-2506, 2003). Tuberculosis and lymphoma are the common diagnosis in patients with clinical features of weight loss, lymphadenopathy, hepatosplenomegaly and lymphocyte predominant ascites. We had a similar presentation in a young male, who was a diabetic, with clinical features suggestive of probable tuberculous infiltration of abdomen and adrenals causing addisonian features, lymphocyte predominant ascites, hepatosplenomegaly and generalized lymphadenopathy. However, a pathological diagnosis of hyaline vascular variant of Castleman's disease was obtained on lymphnode biopsy, which propelled us into doing a skeletal survey and bonemarrow biopsy. A final diagnosis of multicentric Castleman's disease with reactive plasmacytosis was achieved. Patient had osteosclerotic lesion in the right femur with evidence of polyneuropathy, organomegaly, endocrinopathies and skin hyperpigmentation. He has improved on chemotherapy with melphan and dexamethasone. Hyaline vascular variant of Castleman's disease rarely presents with systemic symptoms. Follow up is essential, as they can manifest with complications like POEMS and lymphoma.

Observation of the origin of d0 magnetism in ZnO nanostructures using X-ray-based microscopic and spectroscopic techniques.

Efforts have been made to elucidate the origin of d(0) magnetism in ZnO nanocactuses (NCs) and nanowires (NWs) using X-ray-based microscopic and spectroscopic techniques. The photoluminescence and O K-edge and Zn L3,2-edge X-ray-excited optical luminescence spectra showed that ZnO NCs contain more defects than NWs do and that in ZnO NCs, more defects are present at the O sites than at the Zn sites. Specifically, the results of O K-edge scanning transmission X-ray microscopy (STXM) and the corresponding X-ray-absorption near-edge structure (XANES) spectroscopy demonstrated that the impurity (non-stoichiometric) region in ZnO NCs contains a greater defect population than the thick region. The intensity of O K-edge STXM-XANES in the impurity region is more predominant in ZnO NCs than in NWs. The increase in the unoccupied (occupied) density of states at/above (at/below) the conduction-band minimum (valence-band maximum) or the Fermi level is related to the population of defects at the O sites, as revealed by comparing the ZnO NCs to the NWs. The results of O K-edge and Zn L3,2-edge X-ray magnetic circular dichroism demonstrated that the origin of magnetization is attributable to the O 2p orbitals rather than the Zn d orbitals. Further, the local density approximation (LDA) + U verified that vacancies in the form of dangling or unpaired 2p states (due to Zn vacancies) induced a significant local spin moment in the nearest-neighboring O atoms to the defect center, which was determined from the uneven local spin density by analyzing the partial density of states of O 2p in ZnO.

Optical and photocatalytic properties of single crystalline ZnO at the air-liquid interface by an aminolytic reaction.

Crystalline flowerlike ZnO was synthesized by an aminolytic reaction at the air-liquid interface in an aqueous media at an alkaline pH. A thin visible film was formed at the air-liquid interface by self-assembly of flowerlike ZnO. Diffraction studies show rearrangement of the single crystalline units at the air-liquid interface leading to the formation of nanobelts. These nanobelts overlap systematically to form petals of the flowerlike structure; individual petals get curved with time. Each nanobelt is found to be single crystalline and can be indexed as the hexagonal ZnO phase. The organic product formed in the aminolytic reaction and dissolution-reprecipitation mechanism is the driving force for the formation of flowerlike ZnO at the air-liquid interface. A clear relationship between the surface, photocatalytic, and photoluminescent properties of ZnO is observed. The flowerlike structure exhibits a blue shift (3.56 eV) in the band emission as compared to bulk ZnO (3.37 eV). The photodegradation of methylene blue over the flowerlike ZnO catalyst formed at the air-liquid interface and in the sediments shows enhanced photocatalytic activity. The sub-bands formed due to surface defects facilitate separation of charge carriers increasing their lifetime, leading to enhanced photocatalytic activity of flowerlike ZnO.

Kikuchi-Fujimoto's disease: a report of five cases.

Kikuchi Fujimoto's disease is a rare, self limiting disorder characterized by fever and cervical lymphadenitis. It is often an incidental finding in a patient suspected to have tuberculosis or lymphoproliferative disorder. We diagnosed this disease in a young 23-year-old female who was suffering from prolonged fever, cervical lymphadenopathy, anemia, leucopenia and mild splenomegaly; based on histopathological study of the excised lymphnode. We reviewed the clinical records and histopathologic findings of four more patients of Kikuchi-Fujimoto's disease, who were treated by others at our institute. All five patients improved with NSAIDS (non steroidal anti inflammatory drugs). Histopathological finding of histiocytic necrotizing lymphadenitis or Kikuchi's disease proved invaluable in characterization of these cases.

Lung and lupus vulgaris.

Lupus vulgaris is chronic, postprimary, paucibacillary cutaneous tuberculosis found in individuals with moderate immunity and high degree of tuberculin sensitivity. Eighty percent of the lesions are on the head and neck. We present the case of a 38 year old lady who was admitted with complaints of worsening breathlessness and low grade fever of one month duration. Examination showed multiple, nontender skin ulcers on bilateral lumbar areas, two oozing serosanguinous discharge and others scarred in the centre. Respiratory system examination and chest X-ray revealed right sided pleural effusion. On investigation, pleural fluid was tuberculous in nature. Skin biopsy from the edge of ulcer was also suggestive of tuberculosis. Patient is doing well on antituberculous drugs. This case highlights the importance of cutaneous manifestations of systemic disease and is an example of the unusual presentation of lupus vulgaris in a case of pleural effusion.

Anal stenosis.

Anal stenosis occurs most commonly following a surgical procedure, such as hemorrhoidectomy, excision and fulguration of anorectal warts, endorectal flaps, or following proctectomy, particularly in the setting of mucosectomy. Patients who experience anal stenosis describe constipation, bleeding, pain, and incomplete evacuation. Although often described as a debilitating and difficult problem, several good treatment options are available. In addition to simple dietary and medication changes, surgical procedures, such as lateral internal sphincterotomy or transfers of healthy tissue are other potentially good options. Flap procedures are excellent choices, depending on the location of the stenosis and the amount of viable tissue needed. This article presents the definition, pathophysiology, diagnosis, and treatment of anal stenosis, and methods to prevent it.

High coercivity of oleic acid capped CoFe2O4 nanoparticles at room temperature.

High coercivity (9.47 kOe) has been obtained for oleic acid capped chemically synthesized CoFe(2)O(4) nanoparticles of crystallite size approximately 20 nm. X-ray diffraction analysis confirms the formation of spinel phase in these nanoparticles. Thermal annealing at various temperatures increases the particle size and ultimately shows bulk like properties at particle size approximately 56 nm. The nature of bonding of oleic acid with CoFe(2)O(4) nanoparticles and amount of oleic acid in the sample is determined by Fourier transform infrared spectroscopy and thermogrvimetric analysis, respectively. The Raman analysis suggests that the samples are under strain due to capping molecules. Cation distribution in the sample is studied using Mossbauer spectroscopy. Oleic acid concentration dependent studies show that the amount of capping molecules plays an important role in achieving such a high coercivity. On the basis of above observations, it has been proposed that very high coercivity (9.47 kOe) is the result of the magnetic anisotropy, strain, and disorder of the surface spins developed by covalently bonded oleic acid to the surface of CoFe(2)O(4) nanoparticles.

Template-free ZnS nanorod synthesis by microwave irradiation.

We report template-free, microwave-irradiation-assisted growth of ZnS nanorods. Using this facile and high yield technique we could grow nanostructures of approximately 50-100 nm diameter and more than 1 µm in length. Effects of microwave power and irradiation time on the growth process were investigated. It was revealed that the time of refluxing plays a vital role in determining the thickness of the rods. This simple technique using a multimode microwave source may prove to be a potential tool for growing similar nanostructures of other oxide-, sulfide- and selenide-based compound semiconductors.

Snakebite.

The five families of poisonous snakes are: Viperidae, elapidae, colubridae, hydrophidae, atractaspididae. The commonly seen snakes in India are saw scaled viper, Russell's viper, common cobri and common crait. The venom of a single snake contains all the toxins. The venom of viperidae is haemotoxic. It may complicate with acute renal failure if left untreated. The venom of elapidae is neurotoxic. Management consists in two parts-general and specific. Supportive treatment is done with the use of antibiotics and tetanus immunoglobulin/toxoid. Specific therapy for viper bite is elaborated in this article. Elapid bite and hydrophidae bites are also discussed. Prevention of snakebite is done with avoidance of contact with a snake by using protective knee length footwear and thick gloves. Venom toxoids are used for secondary prevention among the farmers of Japan.