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Nonlinear optical properties of a selection of gallium nitride samples have been measured using picosecond and nanosecond duration laser pulses at 532 nm. The values of the two-photon absorption coefficient, free carrier absorption cross section, and free carrier refraction cross section are determined along with the recombination lifetime of photogenerated carriers. The effect of hot isostatic pressing on these properties in samples with linear absorption at the band edge due to defects is explored.

Prostate cancer (CaP) remains the most commonly diagnosed malignancy and the second leading cause of cancer related deaths in men in the US. While the 5-year survival rate for patients with localized CaP is over 99%, it is only 30% for patients with distant metastases. Despite impressive advances in the treatment of metastatic CaP with more efficacious inhibitors along the androgen/androgen receptor axis, eventual development of incurable metastatic Castration Resistant Prostate Cancer (mCRPC) is inevitable, necessitating the development of newer therapeutic strategies. Comprehensive evaluations of CaP genomes from localized and metastatic CaP have revealed that subsets harboring mutations in certain DNA Damage Repair Genes (DDRGs) account for up to 30% of patients. LP184, a novel alkylating agent belonging to the acylfulvene (AF) class is currently in preclinical development, having demonstrated appreciable anticancer activity in multiple prostate tumor models. LP184 exhibits nanomolar potency (20 - 350 nM) against widely used CaP cell lines in 2D culture while having reduced cytotoxicity in a non-tumor prostate epithelial cell line. In CaP cell lines, LP184 turned out equipotent as standard chemotherapeutic Docetaxel, 100-2000 times more potent than another alkylating agent Cisplatin, and 100-9000 times more potent than PARP inhibitor, Olaparib. LP184 is also effective in 3 CaP organoid models 3D cultured from patient-derived xenografts. We hypothesize that LP184 exhibits potent inhibitory effects on CaP cells through a compromised DNA repair milieu of mCRPC due to damaging DDRG mutations in BRCA2, FANCI, ERCC3, ERCC6, FANCG, PALB2 and ATM represented by the in vitro CaP models tested. DNA damage resulting from AF treatment is known to be processed exclusively via transcription coupled nucleotide excision repair. Consistent with this, we observed enhanced LP-184 sensitivity in a cell line model with truncated ERCC3 relative to the otherwise syngeneic parental cell line. Based on Connectivity Map (CMAP) analysis of full transcriptome profiling data on LP184 treatment in selected CaP cell lines, we identified potential drug classes including PARP inhibitors, proteasome inhibitors, topoisomerase inhibitors and MTOR inhibitors that emerged in silico as synergistic with LP184. This approach utilized matching of genes differentially expressed upon LP184 exposure compared to 5000 other small molecules within CMAP. Advancement of LP184, potentially exploiting recurrent and actionable DDRG mutations, is anticipated to be translated into future clinical trials for mCRPC, a lethal CaP that is responsible for ~33,000 deaths/year in the US alone. Given that only a subset of patients responds to any single drug in this advanced CaP stage, LP184 stands out as a unique agent that may complement or synergize with drugs currently used in treatment of mCRPC and improve the outcomes for men with lethal CaP. Citation Format: Aditya Kulkarni, Partha Banerjee, Umesh Kathad, Kishor Bhatia, Panna Sharma. LP184, a novel alkylating agent, is efficacious in prostate cancer models with DNA damage repair defects [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1249.

The dependence of static, high frequency and noise characteristics of Silicon based magnetic field tunable avalanche transit time (MAGTATT) sources operating at millimeter-wave atmospheric window frequencies (94, 140 and 220 GHz) and two different terahertz (THz) frequencies (0.3 and 0.5 THz) have been investigated in this paper. Comprehensive two-dimensional simulation models developed by the authors for evaluating static, large-signal and noise characteristics of MATATT diodes have been used for this purpose. The simulation results show that the above-mentioned magnetic field sensitivities are considerably reduced as the operating frequency increases.

The effect of magnetic field on the noise performance of the magnetic field tunable avalanche transit time (MAGTATT) device based on Si, designed to operate at W-band (75 – 110 GHz), has been studied in this paper. A comprehensive two-dimensional (2D) model has been developed. The simulation results show that due to the presence of applied external transverse magnetic field, both the noise spectral density and noise measure of the MAGTATT device increase significantly. The noise performance of the device has been found to be further deteriorated if the magnetic field strength is further increased. Hence, in order to achieve the magnetic field tuning of the radio frequency (RF) properties of impact avalanche transit time (IMPATT) source, the noise performance of it has to be sacrificed in fair extent. Moreover, it clearly indicates that an IMPATT source must be covered with appropriate magnetic shielding material to avoid undesirable shift in operating frequency and output power and objectionable amount of deterioration in noise performance due to the presence of external magnetic field.

In this paper, a two-dimensional (2-D) large-signal model has been presented to study the effect of steady magnetic field on the RF performance of millimeter-wave (mm-wave) double-drift region impact avalanche transit time device. Magnetic field sensitivities of various static and large-signal parameters of the device designed to operate at W-band have been calculated and discussed in detail. Results show that the frequency tuning of the source of around 3.64 GHz is achievable with maximum sensitivity of about $$-$$-1.59 GHz $$\hbox {T}^{-1}$$T-1 for the application of transverse magnetic field varying from 4.0 to 5.0 T. The nature of both frequency and power tuning of the device due to application of transverse magnetic field is in good agreement with the experimental results carried out earlier.

The Second Edition of the bestselling Measurement, Instrumentation, and Sensors Handbook brings together all aspects of the design and implementation of measurement, instrumentation, and sensors. Reflecting the current state of the art, it describes the use of instruments and techniques for performing practical measurements in engineering, physics, chemistry, and the life sciences and discusses processing systems, automatic data acquisition, reduction and analysis, operation characteristics, accuracy, errors, calibrations, and the incorporation of standards for control purposes. Organized according to measurement problem, the Spatial, Mechanical, Thermal, and Radiation Measurement volume of the Second Edition: Contains contributions from field experts, new chapters, and updates to all 96 existing chapters Covers instrumentation and measurement concepts, spatial and mechanical variables, displacement, acoustics, flow and spot velocity, radiation, wireless sensors and instrumentation, and control and human factors A concise and useful reference for engineers, scientists, academic faculty, students, designers, managers, and industry professionals involved in instrumentation and measurement research and development, Measurement, Instrumentation, and Sensors Handbook, Second Edition: Spatial, Mechanical, Thermal, and Radiation Measurement provides readers with a greater understanding of advanced applications.

In this paper, we present a two phase cooperative relaying scheme for spectrum sharing in a 2 × 2 overlay cognitive radio. Secondary transmitter acts as decode and forward relay to the primary and employs hierarchical modulation to enhance primary SNR reception. Primary receiver employs cooperative maximal ratio combining to improve SNR and secondary receiver recovers its own data by successive interference cancellation. We have calculated symbol error rate (SER) analytically for such system and optimal power allocation factor between primary and secondary data in hierarchical modulation have been found out. The analytical result of SER is found close agreement with Monte-Carlo simulation.

The modulation of millimetre-wave (mm-wave) and terahertz (THz) properties of impact avalanche transit time (IMPATT) sources under external steady magnetic field has been studied in this paper. The arrangement of magnetic field tuning of IMPATT oscillators by using external transverse steady magnetic field is referred to as magnetic field tunable avalanche transit time (MAGTATT) oscillators. The sensitivities of various static, large-signal and noise characteristics of silicon-based MAGTATT sources operating at mm-wave atmospheric window frequencies (94, 140 and 220 GHz) and two different THz frequencies (0.3 and 0.5 THz) have been studied. Comprehensive two-dimensional simulation models developed by the authors for evaluating static, large-signal and noise characteristics of MATATT diodes have been used for this purpose. The simulation results show that the above-mentioned magnetic field sensitivities of the device properties are significantly reduced with the increase of the operating frequency.

Purpose – The purpose of this paper was development of patient-specific femoral prosthesis using rapid prototyping (RP), a part of additive manufacturing (AM) technology, and comparison of its merits or demerits over CNC machining route. Design/methodology/approach – The customized femoral prosthesis was developed through computed tomography (CT)-3D CAD-RP-rapid tooling (RT)-investment casting (IC) route using a stereolithography apparatus (SLA-250) RP machine. A similar prosthesis was also developed through conventional CT-CAD-CAM-CNC, using RP models to check the fit before machining. The dimensional accuracy, surface finish, cost and time involvement were compared between these two routes. Findings – In both the routes, RP had an important role in checking the fit. Through the conventional machining route, higher-dimensional accuracies and surface finish were achieved. On the contrary, RP route involved lesser time and cost, with rougher surface finish on the prosthesis surface and less internal shrinkage porosity. The rougher surface finish of the prosthesis is favourable for bone ingrowths after implantation and porosity reduce the effective stiffness of the prosthesis, leading to reduced stress shielding effect after implantation. Research limitations/implications – As there is no AM machine for direct fabrication of metallic component like laser engineered net shaping and electron beam melting in our Institute, the metallic prosthesis was developed through RP-RT-IC route using the SLA-250 machine. Practical implications – The patient-specific prosthesis always provides better fit and favourable stress distribution, leading to longer life of the prosthesis. The described RP route can be followed to develop the customized prosthesis at lower price within the shortest time. Originality/value – The described methodology of customized prosthesis development through the AM route and its advantages are applicable for development of any metallic prostheses.

The increasing older population is suffering from an increase in age-related spinal degeneration that causes tremendous pain. Spine injury is mostly indicated at the lumbar spine (L3-L5) and corresponding intervertebral disks. Finite element analysis (FEA) is now one of the most efficient and accepted tools used to simulate these pathological conditions in computer-assisted design (CAD) models. In this study, L3-L5 spines were modeled, and FEA was performed to formulate optimal remedial measures. Three different loads (420, 490.5, and 588.6 N) based on three body weights (70, 90, and 120 kg) were applied at the top surface of the L3 vertebra, while the lower surface of the L5 vertebra remained fixed. Models of implants using stainless steel and titanium alloy (Ti6Al4V) pedicle screws and rods with three different diameters (4, 5, and 6 mm) were inserted into the spine models. The relative strengths of bone (very weak, weak, standard, strong, and very strong) were considered to determine the patient-specific effect. A total of 90 models were simulated, and von Mises stress and strain, shear stress, and strain intensity contour at the bone-implant interface were analyzed. Results of these analyses indicate that the 6-mm pedicle screw diameter is optimal for most cases. Experimental and clinical validation are needed to confirm these theoretical results.

Influences of magnetic field on the noise performance of double-drift region (DDR) impact avalanche transit time (IMPATT) device based on Si designed to operate within W-band (75–110 GHz) have been studied in this paper. The reverse biased DDR IMPATT structure under transverse magnetic field can be regarded as magnetic field tunable avalanche transit time (MAGTATT) device. The simulation results show that both the noise spectral density and noise measure of the device increase significantly while the device is kept in transverse magnetic field. This degradation of the noise performance of the device enhances when the magnitude of the magnetic field is increased. Therefore, in order to achieve the magnetic field tuning of the RF properties of DDR IMPATTs as reported earlier by the authors, the noise performance of the source has to be sacrificed in fair extent.

In today’s competitive world, the life-style of the average human being has become very fast. This causes a huge number traffic accidents resulting in various types of injuries. In India, most of these accidents take place during bike riding and this causes different types of fracture of bones. One of these injuries is head injury. For the proper treatment of such patients, demands for patient-specific craniofacial bio-implants are increasing day by day. This kind of ‘tailored’ implant development through near net shape manufacturing is a highly challenging task since the developmental time and cost has to be as low as possible. At the Central Mechanical Engineering Research Institute (CMERI), one such process of implant development was explored taking one case of head injury. The implant was developed through the “3D CAD-rapid prototyping (RP)-rapid tooling (RT)-investment casting (IC)” route. For achieving the task, only the facilities available at CMERI were utilized.

In vitro time-kill studies and a rabbit model of endocarditis and pyelonephritis were used to define the impact that the order of exposure of Candida albicans to fluconazole (FLC) and amphotericin B (AMB), as sequential and combination therapies, had on the susceptibility of C. albicans to AMB and on the outcome. The contribution of FLC-induced resistance to AMB for C. albicans also was assessed. In vitro, AMB monotherapy rapidly killed each of four C. albicans strains; FLC alone was fungistatic. Preincubation of these fungi with FLC for 18 h prior to exposure to AMB decreased their susceptibilities to AMB for 8 to >40 h. Induced resistance to AMB was transient, but the duration of resistance increased with the length of FLC preincubation. Yeast sequentially incubated with FLC followed by AMB plus FLC (FLC→AMB+FLC) showed fungistatic growth kinetics similar to that of fungi that were exposed to FLC alone. This antagonistic effect persisted for at least 24 h. Simultaneous exposure of C. albicans to AMB and FLC [AMB+FLC(simult)] demonstrated activity similar to that with AMB alone for AMB concentrations of ≥1 μg/ml; antagonism was seen using an AMB concentration of 0.5 μg/ml. The in vitro findings accurately predicted outcomes in our rabbit infection model. In vivo, AMB monotherapy and treatment with AMB for 24 h followed by AMB plus FLC (AMB→AMB+FLC) rapidly sterilized kidneys and cardiac vegetations. AMB+FLC(simult) and FLC→AMB treatments were slower in clearing fungi from infected tissues. FLC monotherapy and FLC→AMB+FLC were both fungistatic and were the least active regimens. No adverse interaction was observed between AMB and FLC for the AMB→FLC regimen. However, FLC→AMB treatment was slower than AMB alone in clearing fungi from tissues. Thus, our in vitro and in vivo studies both demonstrate that preexposure of C. albicans to FLC reduces fungal susceptibility to AMB. The length of FLC preexposure and whether AMB is subsequently used alone or in combination with FLC determine the duration of induced resistance to AMB.

Optimized experimental setup is developed for the production of metal and metal oxide nanoparticles. The electrical behavior of the explosion wire in LCR circuit and energy deposition is studied which leads to the production of mixed phase crystalline copper oxide. Stored energy of the system is varied to produce the nanoparticles to study the effect of the energy deposition in the formation of nanoparticle.

The rhizoplane mycofloras of little bluestem (Schizachyrium scoparium) were compared in unfumigated and fumigated soils to which selected inorganic nutrients were added. Thirty-four fungal taxa were isolated and 20 were common to unfumigated and fumigated soil 17 months after fumigation. Species richness (i.e., number of species) was greater on the unfumigated site (33 species) than the fumigated site (21 species). Addition of inorganic nutrients to the soil did not have significant effects on the occurrence of the eight most abundant rhizoplane species. Tests for interspecific association among the eight most frequently occurring species revealed that most of these species had significant negative associations with each other.

A large number of orthopaedically handicapped patients in India require treatment with suitable low-cost implants of varied sizes and shapes, which has become a crucial problem today. Out of these patients, the case of degenerative hip joints is around one-half million every year, the majority of which are total hip replacements. For most of these cases, the surgery is done with imported implants, which may not be in keeping with the osteological dimensions of Indian patients. To explore this area, a study was done at CMERI on computed tomographic (CT) scan data of the proximal region of the femur bone of patients from different regions of India. Since the problem is prominent with the elderly populations who are above 50 years of age, the CT scan data was collected for patients with age of 50-78 years. In this study, 23 selected osteological dimensions of each femur were measured in a CAD environment from CT scan data of around 100 elderly Indian patients. The measured parameters were statistically analyzed to find out the variations and stepping of dimensions. Depending on these data, the stem of hip implant was designed with different sizes, suitable for Indian patients. The devices were then analyzed in finite element analysis packages individually, as well as by putting the device inside the femur bone, as an actual case. After this analysis, some modifications were required and it was found that after implantation the stress induced in the implant and bone would be well within permissible limits.

A field study of rhizoplane microfungi associated with little bluestem (Schizachyrium scoparium (Michx.) Nash), a common tallgrass prairie species, had indicated thatPenicillium chrysogenum Thom andTrichoderma harzianum Rifai outcompeted each other in unfumigated and fumigated soils, respectively. To investigate the mechanisms of competition, interactions between the two fungi were studied in laboratory experiments using an artificial model system. Mutual suppression did occur. The first-inoculated fungus was less affected. Some detrimental residual effects on the growth of one species were observed when it was grown along with the killed mass of the other in the same medium.

Basidiospore germination is a critical first step in carrying out mating behavior studies (Watling, 1971), yet some basidiospores, particularly spores of mycorrhizal organisms, do not easily germinate in vitro (Fries, 1977, 1978). Numerous experimental procedures have been employed to accomplish spore germination (e.g., Fries, 1977, 1978,1983,1990; Fries and Mueller, 1984). Fries (1990) has shown the effects of tree roots on spore germination of ectomycorrhizal fungi. Fries (1983) and Fries and Mueller (1984) among other workers improvised nutritive media to obtain basidiospore germination of Laccaria, an ecto? mycorrhizal fungus. Short-term cold storage has been found beneficial in spore germination of vesicular-arbuscular mycorrhizal fungi (Safir et al., 1990). Even though Pluteus (Pluteaceae, Agaricales) is presumably nonmycorrhizal, attempts to germinate its basidiospores have been unsuccessful (Smith, 1971; Watling, 1971). The following experiments were performed, there? fore, to test the effects of some environmental parameters on germination of Pluteus basidio? spores and germ tube growth under laboratory conditions.

The interaction between fluconazole (Flu) and amphotericin B (AmB) was evaluated in a murine model of systemic candidiasis for one Flu-susceptible strain (MIC, 0.5 μg/ml), two strains with intermediate Flu resistance (Flu mid-resistant strains) (MIC, 64 and 128 μg/ml), and one highly Flu-resistant strain (MIC, 512 μg/ml) of Candida albicans . Differences in fungal densities in kidneys of infected mice after 24 h of therapy and in survival rates at 62 days of mice treated with an antifungal drug or a combination of antifungal drugs for 4 days were compared. For the Flu-susceptible and Flu mid-resistant strains, the combination of Flu and AmB was antagonistic, as shown by both quantitative culture results and survival. The interaction was additive for the highly Flu-resistant strain. These results suggest that the combination of Flu and AmB should be used with caution in infections due to fungi that are usually susceptible to both antifungal agents and as empirical antifungal drug therapy.

In this study we defined the pharmacodynamic parameter that optimizes outcome in deep-seated Candida albicans infections treated with fluconazole. Using a murine model of systemic candidiasis, we conducted single-dose dose-ranging studies with fluconazole to determine the dosage of this drug that resulted in a 50% reduction in fungal densities (50% effective dose [ED 50 ]) in kidneys versus the fungal densities in the kidneys of untreated controls. We found that the ED 50 of fluconazole given intraperitoneally was 4.56 mg/kg of body weight/day (95% confidence interval, 3.60 to 5.53 mg/kg/day), and the dose-response relationship was best described by an inhibitory sigmoid maximal effect ( E max ) curve. To define the pharmacodynamics of fluconazole, we gave dosages lower than, approximating, and higher than the ED 50 of fluconazole (range, 3.5 to 5.5 mg/kg/day, equivalent to the ED 16 to the ED 75 ) to various groups of infected animals using three dose-fractionation schedules. For each total dose of fluconazole examined, the dose-fractionation schedules optimized the ratio of the area under the concentration-time curve (AUC) to the MIC (the AUC/MIC ratio), the ratio of the maximum concentration of drug in serum ( C max ) to the MIC, and the time that the drug remained above the MIC for the infecting C. albicans isolate. Similar reductions in fungal densities in kidneys were seen between groups that received the same total dose of fluconazole in one, two, or four equally divided doses. Thus, dose-fractionation studies demonstrated that the pharmacodynamic parameter of fluconazole that best predicted outcome was the AUC/MIC ratio.

The light-induced scattering in photorefractive crystals has been investigated widely by many researchers because it has important effects on photorefractive holograms, phase conjugation, etc. The characteristics of the pattern of the light-induced scattering depend on polarization and orientation of the illumination beam relative to the crystallographic axes of the crystal. Most studies of the light-induced scattering to date were performed with LiNbO3:Fe, LiTaO3, and BaTiO3 crystals at fixed distances between focusing lenses and samples.[1,2,3] KNbO3 is an important crystal used in two-wave mixing, phase conjugation, and dynamic holography. This paper presents the features of light-induced scattering and "position dispersion" of KNbO3:Fe crystal. The anisotropic scattering from the KNbO3:Fe crystal is shown to be dominated by light-induced lensing.

Optical technology has become a significant part of communication networks. We propose an optical interface message processor (OPTIMP) that exploits high bandwidth, parallelism, multidimensional capability, and high storage density. The most time-consuming operations in communication networks, such as switching and routing, are performed in the optical domain in the proposed system. Furthermore, the OPTIMP does not suffer from optical/electrical conversion bottle-necks and can perform switching and routing in the range of gigabits/s. OPTIMP has three main functional modules: a timespace conversion module, a parallel search and routing look-up table, and an optically controlled switching module. The sourcedestination (SD) information from a message is first converted to the spatial domain. The routing table stores all SD codes and the corresponding control codes for the switching module. The SD code serves as a microprogrammed instruction (similar to that in processor designs). The routing table is searched in parallel (single step) by means of a cylindrical system, and control signals corresponding to the matched S-D row from the table are used to control the switching network. Based on the SEED array technology, the switching module can be reconfigured in gigahertz range and can provide high bandwidth. The proposed design can have significant application to high-speed communication networks as well as to high-speed interconnection networks for parallel computers.