Down-conversion luminescence nanocomposites based on nitrogen-doped carbon quantum dots@bioplastic for applications in optical displays, LEDs and UVC tubes.

Carbon quantum dots (CQDs)-based composites as luminous down-conversion materials are becoming more popular due to several advantages such as steady fluorescence, ease of functionalization, tailoring of emission in the visible range, and so on. We report an inexpensive and environmentally sustainable synthesis of fluorescent nitrogen doped-CQDs produced from Cissus quadrangularis, a low-cost plant precursor with therapeutic value. The morphological, structural, and physicochemical features of the material were carefully investigated. Under UV stimulation (365 nm), almost spherical shaped N-CQDs with an average diameter of 5.1 nm were discovered to generate yellow-green fluorescence, have excellent photostability, and strong water solubility, with a quantum yield of up to 5 %. Furthermore, as a solid-phase dispersion matrix for CQDs, ecologically friendly and biodegradable bioplastic is appealing. The down-conversion of solid-state fluorescence of LEDs and UVC tubes was demonstrated by creating a nanocomposite by inserting N-CQDs into the solid matrix of a wheat starch-based bioplastic. Furthermore, employing constructed quantum dot-based optical displays, down-converted LEDs, and UVC tubes, the impacts of varied CQD concentrations and pH sensitivity were examined.

Oxygen isotope in archaeological bioapatites from India: Implications to climate change and decline of Bronze Age Harappan civilization.

The antiquity and decline of the Bronze Age Harappan civilization in the Indus-Ghaggar-Hakra river valleys is an enigma in archaeology. Weakening of the monsoon after ~5 ka BP (and droughts throughout the Asia) is a strong contender for the Harappan collapse, although controversy exists about the synchroneity of climate change and collapse of civilization. One reason for this controversy is lack of a continuous record of cultural levels and palaeomonsoon change in close proximity. We report a high resolution oxygen isotope (δ(18)O) record of animal teeth-bone phosphates from an archaeological trench itself at Bhirrana, NW India, preserving all cultural levels of this civilization. Bhirrana was part of a high concentration of settlements along the dried up mythical Vedic river valley 'Saraswati', an extension of Ghaggar river in the Thar desert. Isotope and archaeological data suggest that the pre-Harappans started inhabiting this area along the mighty Ghaggar-Hakra rivers fed by intensified monsoon from 9 to 7 ka BP. The monsoon monotonically declined after 7 ka yet the settlements continued to survive from early to mature Harappan time. Our study suggests that other cause like change in subsistence strategy by shifting crop patterns rather than climate change was responsible for Harappan collapse.

Primary synovial sarcoma of the kidney.

Primary synovial sarcoma (SS) of the kidney is a very rare disease as well as a diagnostic dilemma. Here, we present a case of a 60-year-old male clinically diagnosed as renal cell carcinoma. The radical nephrectomy specimen showed a well-circumscribed renal mass of approximately 13 cm × 9 cm × 7 cm. The cut-surface of the mass was tawny and firm, with cystic areas, and also showed focal hemorrhage and necrosis. Histologically, the tumor was composed of spindle cells arranged in the intersecting fascicles, alternating with hypocellular areas suggestive of monophasic synovial sarcoma. Morphological and immunohistochemical features were compatible with the diagnosis of SS of the kidney.

Reversible monolayer-to-crystalline phase transition in amphiphilic silsesquioxane at the air-water interface.

We report on the counter intuitive reversible crystallisation of two-dimensional monolayer of Trisilanolisobutyl Polyhedral Oligomeric SilSesquioxane (TBPOSS) on water surface using synchrotron x-ray scattering measurements. Amphiphilic TBPOSS form rugged monolayers and Grazing Incidence X-ray Scattering (GIXS) measurements reveal that the in-plane inter-particle correlation peaks, characteristic of two-dimensional system, observed before transition is replaced by intense localized spots after transition. The measured x-ray scattering data of the non-equilibrium crystalline phase on the air-water interface could be explained with a model that assumes periodic stacking of the TBPOSS dimers. These crystalline stacking relaxes upon decompression and the TBPOSS layer retains its initial monolayer state. The existence of these crystals in compressed phase is confirmed by atomic force microscopy measurements by lifting the materials on a solid substrate.

Switching mechanism in Au nanodot-embedded Nb2O5 memristors.

Resistive switching behavior of Au nanodot-embedded Nb2O5 memristor devices is reported. Due to controlled formation and/or rupture of conductive filaments; Au nanodot-embedded Nb2O5 devices show better consistency during transition from high to low resistance state and vice-versa. The memristive transition is explained using a physical model which involves oxygen ion, O(2-) trapping or detrapping at the metal-oxide interface, and O(2-) transport and annihilation with the oxygen vacancies in the breakdown percolation path. The experimental results indicate that Au nanodot-embedded Nb2O5 memristors may find applications as non-volatile memory devices.

Genito-urinary tuberculosis revisited--13 years' experience of a single centre.

BACKGROUND: Tuberculosis had been declared by the World Health Organization (WHO) as 'public health emergency' in 1993. Extra pulmonary tuberculosis (E.P.T.B.) comprises 20-25% total burden of the disease in which genitourinary tuberculosis (GU.T.B.) is 4%. Timely diagnosis and treatment will prevent the sequelae of this disease. AIMS: To know the varied clinical presentations, diagnostic modalities and management of G.U.T.B. METHODS: During a 13-year-period, 117 retrospective cases of GUTB were admitted in the tertiary care centre. They were analyzed for clinical presentation, diagnostic modalities and management. RESULTS: Young patients mainly in third decade of life were commonly affected with higher incidence in females. In our study, the most common presentation was irritative voiding symptoms (66.47%) followed by haematuria (47.60%). Although it can affect the entire organ in genito-urinary system but, in the present study, kidney was the most affected organ (64.9%) following ureter (27.35%), urinary bladder (17.09%), prostate (3.4%) and epididymis (5.19%). In this study, we had not encountered any case of testicular and penile tuberculosis. Among the different diagnostic modalities in this study, the diagnostic positivity rate was 41.6% for the urine AFB test, 55.4% for the urine M. tuberculosis culture test and 67.7% for PCR. Chest x-ray was positive in 25.6% (30). ESR was raised in 62.5% and Mantoux test was positive in 61.2% patients. CONCLUSION: A high index of suspicion and a wide range of investigations may be required to achieve a complete diagnosis of genitourinary tuberculosis. Though short course chemotherapy with four-drug-regimen for six-month-duration is the mainstay of treatment, surgical interventions were required in 60% of cases of this study.

The safety and efficacy of endoscopic incision of orthotopic ureterocele in adult.

Endoscopic incision is a good management option for orthotopic ureterocele. But most of the literature has shown its efficacy only in children. We have done this retrospective study to evaluate the safety and efficacy of endoscopic incision of orthotopic ureterocele in adults. From March 2004 to January 2008, at our center, 26 adults underwent transurethral, transverse incision of an ureterocele. The perioperative data of these patients were retrospectively analyzed. The literature was reviewed to identify all the reported options for management of this relatively rare condition in adults. Unilateral ureterocele was present in 24 patients and two patients had bilateral ureterocele. One patient had associated upper tract stones. Three patients had associated stones in ureterocele. Transurethral, transverse incision of ureterocele was given in all patients. The mean postoperative hospital stay was 50.5 h. Twenty-three patients were available for follow-up at three, six and 12 months. All patients were symptom free. At three months ultrasound and intravenous urography revealed no residual ureterocele but four patients showed residual hydronephrosis, but with a decrease in the grade indicating decompression. Micturating cystourethrography revealed vesico-ureteral reflux (VUR) in two patients and the reflux persisted in one patient even at 6 months. We conclude that in adults, management with endoscopic incision of orthotopic ureterocele is safe and effective. VUR may occur in a few cases.

Structural reordering in monolayers of gold nanoparticles during transfer from water surface to solid substrate.

Structural reordering in monolayers of gold nanoparticles during transfer from water surface to solid substrate has been studied by synchrotron x-ray scattering techniques. Grazing incidence diffraction (GID) and grazing incidence x-ray off-specular scattering (GIXOS) measurements were performed as a function of time to track the in-plane and out-of-plane structural reordering in the transferred monolayers. GID measurements show shift in the in-plane particle-particle correlation peak toward the lower in-plane momentum transfer value, signifying possible expansion of triangular lattice formed on the water surface. However, GIXOS data and supportive microscopy measurements clearly show compactification in the in-plane structure and associated out-of-plane movements. A model that assumes the possibility of a two-dimensional short-range structural reordering from triangular to square-like lattice as a function of time could explain all the data. The observed change in the electron densities of the nanoparticles before and after the structural reordering matches well with the expected change in the calculated electron densities of the nanoparticles arranged in triangular (pretransition) and square-like (post-transition) symmetry.

An unusual cause of ureteral obstruction-role of magnetic resonance imaging.

We report an unusual cause of right ureteral obstruction by a normal running right spermatic vein in a 55-year-old man. Laparoscopic resection of the right spermatic vein was done. To the best of our knowledge, only 1 such case has been previously reported.

Vesicoscopic ureterotomy: novel technique for management of posttransplant ureteric stricture.

Ureteral obstruction following renal transplantation is not an uncommon complication. Open surgery has been the traditional approach. In recent years, retrograde endourologic techniques have been used to manage this complication with good results. In cases of failure of retrograde catheterization of the neomeatus, a percutaneous approach is employed. We present a new technique of pneumovesicoscopic ureterotomy in case of posttransplant ureteric stricture, with failure of retrograde catheterization. This simple, minimally invasive approach for these patients avoids transplant kidney puncture.

Laparoscopic versus open pyeloplasty: Comparison of two surgical approaches -- a single centre experience of three years.

BACKGROUND: Ureteropelvic junction obstruction (UPJO) causes hydronephrosis and progressive renal impairment may ensue if left uncorrected. Open pyeloplasty remains the standard against which new technique must be compared. We compared laparoscopic (LP) and open pyeloplasty (OP) in a randomized prospective trial. MATERIALS AND METHODS: A prospective randomized study was done from January 2004 to January 2007 in which a total of 28 laparoscopic and 34 open pyeloplasty were done. All laparoscopic pyeloplasties were performed transperitoneally. Standard open Anderson Hynes pyeloplasty, spiral flap or VY plasty was done depending on anatomic consideration. Patients were followed with DTPA scan at three months and IVP at six months. Perioperative parameters including operative time, analgesic use, hospital stay, and complication and success rates were compared. RESULTS: Mean total operative time with stent placement in LP group was 244.2 min (188-300 min) compared to 122 min (100-140 min) in OP group. Compared to OP group, the post operative diclofenac requirement was significantly less in LP group (mean 107.14 mg) and OP group required mean of (682.35 mg). The duration of analgesic requirement was also significantly less in LP group. The postoperative hospital stay in LP was mean 3.14 Days (2-7 days) significantly less than the open group mean of 8.29 days (7-11 days). CONCLUSION: LP has a minimal level of morbidity and short hospital stay compared to open approach. Although, laparoscopic pyeloplasty has the disadvantages of longer operative time and requires significant skill of intracorporeal knotting but it is here to stay and represents an emerging standard of care.