76 research outputs found

    A Millimeter-scale Single Charged Particle Dosimeter for Cancer Radiotherapy

    Full text link
    This paper presents a millimeter-scale CMOS 64×\times64 single charged particle radiation detector system for external beam cancer radiotherapy. A 1×\times1 μm2\mu m^2 diode measures energy deposition by a single charged particle in the depletion region, and the array design provides a large detection area of 512×\times512 μm2\mu m^2. Instead of sensing the voltage drop caused by radiation, the proposed system measures the pulse width, i.e., the time it takes for the voltage to return to its baseline. This obviates the need for using power-hungry and large analog-to-digital converters. A prototype ASIC is fabricated in TSMC 65 nm LP CMOS process and consumes the average static power of 0.535 mW under 1.2 V analog and digital power supply. The functionality of the whole system is successfully verified in a clinical 67.5 MeV proton beam setting. To our' knowledge, this is the first work to demonstrate single charged particle detection for implantable in-vivo dosimetry

    Raman Signatures of Strong Kitaev Exchange Correlations in (Na1x_{1-x}Lix_x)2_2IrO3_3 : Experiments and Theory

    Full text link
    Inelastic light scattering studies on single crystals of (Na1x_{1-x}Lix_x)2_2IrO3_3 (x=0,0.05x = 0, 0.05 and 0.150.15) show a polarization independent broad band at \sim ~2750 cm1^{-1} with a large band-width 1800\sim 1800~cm1^{-1}. For Na2_2IrO3_3 the broad band is seen for temperatures 200 \leq 200~K and persists inside the magnetically ordered state. For Li doped samples, the intensity of this mode increases, shifts to lower wave-numbers and persists to higher temperatures. Such a mode has recently been predicted (Knolle et.al.) as a signature of the Kitaev spin liquid. We assign the observation of the broad band to be a signature of strong Kitaev-exchange correlations. The fact that the broad band persists even inside the magnetically ordered state suggests that dynamically fluctuating moments survive even below TNT_{N}. This is further supported by our mean field calculations. The Raman response calculated in mean field theory shows that the broad band predicted for the spin liquid state survives in the magnetically ordered state near the zigzag-spin liquid phase boundary. A comparison with the theoretical model gives an estimate of the Kitaev exchange interaction parameter to be JK57J_K\approx 57~meV.Comment: 14pages 4 figure

    Preparation and evaluation of mouth dissolving tablets of meloxicam

    Get PDF
    The aim of the present study was to develop evaluate mouth dissolving tablet of meloxicam. Drug delivery systems became sophisticated as pharmaceutical scientists acquire a better understanding of the physicochemical and biochemical parameters pertinent to their performance. Over the past three decades, mouth dissolving or orally disintegrating tablets have gained considerable attention as a preferred alternative to conventional tablets due to better patient compliance. The most preferrable route of drug administration (e.g. oral) is limited to drug candidate that show poor permeability across the gastric mucosa and those, which are sparingly soluble. A large majority of the new chemical entities and many new existing drug molecules are poorly soluble, thereby limiting their potential uses and increasing the difficulty of formulating bioavailable drug products,so lastlly the purpose of this study was to grow mouth dissolve tablets of Meloxicam. Meloxicam is a newer selective COX-1 inhibitor. These tablets were prepared by wet granulation procedure. The tablets were evaluated for % friability, wetting time and disintegration time. Sublimation of camphor from tablets resulted in better tablets as compared to the tablets prepared from granules that were exposing to vacuum. The systematic formulation approach helped in understanding the effect of formulation processing variables.Keywords: Mouth dissolving tablet; Maloxicam; Bioavailability; NSAI

    Preparation and evaluation of mouth dissolving tablets of meloxicam

    Get PDF
    The aim of the present study was to develop evaluate mouth dissolving tablet of meloxicam. Drug delivery systems became sophisticated as pharmaceutical scientists acquire a better understanding of the physicochemical and biochemical parameters pertinent to their performance. Over the past three decades, mouth dissolving or orally disintegrating tablets have gained considerable attention as a preferred alternative to conventional tablets due to better patient compliance. The most preferrable route of drug administration (e.g. oral) is limited to drug candidate that show poor permeability across the gastric mucosa and those, which are sparingly soluble. A large majority of the new chemical entities and many new existing drug molecules are poorly soluble, thereby limiting their potential uses and increasing the difficulty of formulating bioavailable drug products,so lastlly the purpose of this study was to grow mouth dissolve tablets of Meloxicam. Meloxicam is a newer selective COX-1 inhibitor. These tablets were prepared by wet granulation procedure. The tablets were evaluated for % friability, wetting time and disintegration time. Sublimation of camphor from tablets resulted in better tablets as compared to the tablets prepared from granules that were exposing to vacuum. The systematic formulation approach helped in understanding the effect of formulation processing variables.Keywords: Mouth dissolving tablet; Maloxicam; Bioavailability; NSAI

    Phase II TPDCV protocol for pediatric low-grade hypothalamic/chiasmatic gliomas: 15-year update

    Get PDF
    To report long-term results for children with low-grade hypothalamic/chiasmatic gliomas treated on a phase II chemotherapy protocol. Between 1984 and 1992, 33 children with hypothalamic/chiasmatic LGGs received TPDCV chemotherapy on a phase II prospective trial. Median age was 3.0 years (range 0.3–16.2). Twelve patients (36%) underwent STRs, 14 (42%) biopsy only, and seven (21%) no surgery. Twenty patients (61%) had pathologic JPAs, nine (27%) grade II gliomas, and four (12%) no surgical sampling. Median f/u for surviving patients was 15.2 years (range 5.3–20.7); 20 of the 23 surviving patients had 14 or more years of follow-up. Fifteen-year PFS and OS were 23.4 and 71.2%, respectively. Twenty-five patients progressed, of whom 13 are NED, two are AWD, and 10 have died. All children who died were diagnosed and first treated at age three or younger. Age at diagnosis was significantly associated with relapse and survival (P = 0.004 for PFS and P = 0.037 for OS). No PFS or OS benefit was seen with STR versus biopsy/no sampling (P = 0.58 for PFS, P = 0.59 for OS). For patients with JPAs and WHO grade II tumors, the 15-year PFS was 18.8 and 22.2% (P = 0.95) and 15-year OS was 73.7 and 55.6% (P = 0.17), respectively. Upfront TPDCV for children with hypothalamic/chiasmatic LGGs resulted in 15-year OS of 71.2% and 15-year PFS of 23.4%. No survival benefit is demonstrated for greater extent of resection. Age is a significant prognostic factor for progression and survival

    Albumin Nano-Encapsulation of Piceatannol Enhances Its Anticancer Potential in Colon Cancer Via Downregulation of Nuclear p65 and HIF-1 alpha

    Get PDF
    Piceatannol (PIC) is known to have anticancer activity, which has been attributed to its ability to block the proliferation of cancer cells via suppression of the NF-kB signaling pathway. However, its effect on hypoxia-inducible factor (HIF) is not well known in cancer. In this study, PIC was loaded into bovine serum albumin (BSA) by desolvation method as PIC-BSA nanoparticles (NPs). These PIC-BSA nanoparticles were assessed for in vitro cytotoxicity, migration, invasion, and colony formation studies and levels of p65 and HIF-1α. Our results indicate that PIC-BSA NPs were more effective in downregulating the expression of nuclear p65 and HIF-1α in colon cancer cells as compared to free PIC. We also observed a significant reduction in inflammation induced by chemical colitis in mice by PIC-BSA NPs. Furthermore, a significant reduction in tumor size and number of colon tumors was also observed in the murine model of colitis-associated colorectal cancer, when treated with PIC-BSA NPs as compared to free PIC. The overall results indicate that PIC, when formulated as PIC-BSA NPs, enhances its therpautice potential. Our work could prompt further research in using natural anticancer agents as nanoparticels with possiable human clinical trails. This could lead to the development of a new line of safe and effective therapeutics for cancer patients

    Dynamics of Prolyl hydroxylases levels during disease progression in experimental colitis

    Get PDF
    Hypoxia inducible factor (HIF)-prolyl hydroxylase (PHD) inhibitors are shown to be protective in several models of inflammatory bowel disease (IBD). However, these non-selective inhibitors are known to inhibit all the three isoforms of PHD, i.e. PHD-1, PHD-2 and PHD-3. In the present report, we investigated the associated changes in levels of PHDs during the development and recovery of chemically induced colitis in mice. The results indicated that in the experimental model of murine colitis, levels of both, PHD-1 and PHD-2 were found to be increased with the progression of the disease; however, the level of PHD-3 remained the same in group of healthy controls and mice with colitis. Thus, the findings advocated that inhibitors, which inhibited all three isoforms of PHD could not be ideal therapeutics for IBD since PHD-3 is required for normal gut function. Hence, this necessitates the development of new compounds capable of selectively inhibiting PHD-1 and PHD-2 for effective treatment of IBD

    An international prospective study of INICC analyzing the incidence and risk factors for catheter-associated urinary tract infections in 235 ICUs across 8 Asian Countries

    Get PDF
    Background: Identify urinary catheter (UC)-associated urinary tract infections (CAUTI) incidence and risk factors (RF) in 235 ICUs in 8 Asian countries: India, Malaysia, Mongolia, Nepal, Pakistan, the Philippines, Thailand, and Vietnam. Methods: From January 1, 2014, to February 12, 2022, we conducted a prospective cohort study. To estimate CAUTI incidence, the number of UC days was the denominator, and CAUTI was the numerator. To estimate CAUTI RFs, we analyzed 11 variables using multiple logistic regression. Results: 84,920 patients hospitalized for 499,272 patient days acquired 869 CAUTIs. The pooled CAUTI rate per 1,000 UC-days was 3.08; for those using suprapubic-catheters (4.11); indwelling-catheters (2.65); trauma-ICU (10.55), neurologic-ICU (7.17), neurosurgical-ICU (5.28); in lower- middle-income countries (3.05); in upper-middle-income countries (1.71); at public-hospitals (5.98), at private-hospitals (3.09), at teaching-hospitals (2.04). The following variables were identified as CAUTI RFs: Age (adjusted odds ratio [aOR] = 1.01; 95% CI = 1.01-1.02; P < .0001); female sex (aOR = 1.39; 95% CI = 1.21-1.59; P < .0001); using suprapubic-catheter (aOR = 4.72; 95% CI = 1.69-13.21; P < .0001); length of stay before CAUTI acquisition (aOR = 1.04; 95% CI = 1.04-1.05; P < .0001); UC and device utilization-ratio (aOR = 1.07; 95% CI = 1.01-1.13; P = .02); hospitalized at trauma-ICU (aOR = 14.12; 95% CI = 4.68-42.67; P < .0001), neurologic-ICU (aOR = 14.13; 95% CI = 6.63-30.11; P < .0001), neurosurgical-ICU (aOR = 13.79; 95% CI = 6.88-27.64; P < .0001); public-facilities (aOR = 3.23; 95% CI = 2.34-4.46; P < .0001). Discussion: CAUTI rate and risk are higher for older patients, women, hospitalized at trauma-ICU, neurologic-ICU, neurosurgical-ICU, and public facilities. All of them are unlikely to change. Conclusions: It is suggested to focus on reducing the length of stay and the Urinary catheter device utilization ratio, avoiding suprapubic catheters, and implementing evidence-based CAUTI prevention recommendations
    corecore