Quantitative evaluation of the impact of variation of optical parameters on the estimation of blood hematocrit and oxygen saturation for dual-wavelength photoacoustics.

Photoacoustic (PA) spectroscopy is considered to be one of the most effective ways to measure the levels of hematocrit (H) and oxygenation saturation (S O 2) of blood, which are essential for diagnosing blood-related illnesses. This simulation study aims to investigate the impact of individual optical parameters, i.e., optical absorption coefficient (µ a), scattering coefficient (µ s), and anisotropy factor (g), on the accuracy of this technique in estimating the blood properties. We first performed the Monte Carlo simulations, using realistic optical parameters, to obtain the fluence maps for various samples. The wavelengths of the incident light were chosen to be 532, 700, 1000, and 1064 nm. Thereafter, the k-Wave simulations were executed, incorporating those fluence maps to generate the PA signals. The blood properties were obtained using the PA signals. We introduced variations in µ a, µ s, and g ranging from -10% to +10%, -10% to +10%, and -5% to +1%, respectively, at 700 and 1000 nm wavelengths. One parameter, at both wavelengths, was changed at a time, keeping others fixed. Subsequently, we examined how accurately the blood parameters could be determined at physiological hematocrit levels. A 10% variation in µ a induces a 10% change in H estimation but no change in S O 2 determination. Almost no change has been seen for µ s variation. However, a 5% (-5% to 0%) variation in the g factor resulted in approximately 160% and 115% changes in the PA signal amplitudes at 700 and 1000 nm, respectively, leading to ≈125% error in hematocrit estimation and ≈14% deviation in S O 2 assessment when nominal S O 2=70%. It is clear from this study that the scattering anisotropy factor is a very sensitive parameter and a small change in its value can result in large errors in the PA estimation of blood properties. In the future, in vitro experiments with pathological blood (inducing variation in the g parameter) will be performed, and accordingly, the accuracy of the PA technique in quantifying blood H and S O 2 will be evaluated.

Humoral and cellular response of COVID-19 vaccine among solid organ transplant recipients: A systematic review and meta-analysis.

BACKGROUND: We aimed to analyze the humoral and cellular response to standard and booster (additional doses) COVID-19 vaccination in solid organ transplantation (SOT) and the risk factors involved for an impaired response. METHODS: We did a systematic review and meta-analysis of studies published up until January 11, 2022, that reported immunogenicity of COVID-19 vaccine among SOT. The study is registered with PROSPERO, number CRD42022300547. RESULTS: Of the 1527 studies, 112 studies, which involved 15391 SOT and 2844 healthy controls, were included. SOT showed a low humoral response (effect size [ES]: 0.44 [0.40-0.48]) in overall and in control studies (log-Odds-ratio [OR]: -4.46 [-8.10 to -2.35]). The humoral response was highest in liver (ES: 0.67 [0.61-0.74]) followed by heart (ES: 0.45 [0.32-0.59]), kidney (ES: 0.40 [0.36-0.45]), kidney-pancreas (ES: 0.33 [0.13-0.53]), and lung (0.27 [0.17-0.37]). The meta-analysis for standard and booster dose (ES: 0.43 [0.39-0.47] vs. 0.51 [0.43-0.54]) showed a marginal increase of 18% efficacy. SOT with prior infection had higher response (ES: 0.94 [0.92-0.96] vs. ES: 0.40 [0.39-0.41]; p-value < .01). The seroresponse with mRNA-12723 mRNA was highest 0.52 (0.40-0.64). Mycophenolic acid (OR: 1.42 [1.21-1.63]) and Belatacept (OR: 1.89 [1.3-2.49]) had highest risk for nonresponse. SOT had a parallelly decreased cellular response (ES: 0.42 [0.32-0.52]) in overall and control studies (OR: -3.12 [-0.4.12 to -2.13]). INTERPRETATION: Overall, SOT develops a suboptimal response compared to the general population. Immunosuppression including mycophenolic acid, belatacept, and tacrolimus is associated with decreased response. Booster doses increase the immune response, but further upgradation in vaccination strategy for SOT is required.

Consequences of the first and second COVID-19 wave on kidney transplant recipients at a large Indian transplant centre.

BACKGROUND: There is a scarcity of data comparing the consequences of first and second COVID-19 waves on kidney transplant recipients (KTRs) in India. METHODS: We conducted a single-centre retrospective study of 259 KTRs with COVID-19 to compare first wave (March 15-December 31 2020, n = 157) and second wave (April 1-May 31 2021, n = 102). RESULTS: KTRs during second wave were younger (43 vs. 40 years; p-value .04) and also included paediatric patients (0 vs. 5.9%; p-value .003). Symptoms were milder during the second wave (45 vs. 62.7%; p-value .007); COVID-19 positive patients had less frequent cough (32 vs. 13.8%; p-value .001), fever was less frequent (58 vs. 37%; p-value .001), and we observed fewer co-morbidities (11 vs. 20.6%; p-value .04). The percentages of neutrophils (77 vs. 83%; p-value .001) and serum ferritin (439 vs. 688; p-value .0006) were higher during second wave, while lymphocyte counts were reduced (20 vs. 14%; p-value .0001). Hydroxychloroquine (11 vs. 0%; p-value .0001) and tocilizumab (7 vs. 0%; p-value .004) were more frequently prescribed during first wave, while utilization of dexamethasone (6 vs. 27%; p-value .0001) and remdesivir (47 vs. 65%; p-value .03) increased during the second wave. Mucormycosis (1.3 vs. 10%; p-value .01) and ICU admissions (20 vs. 37.2%; p-value .002) were more frequent during second wave. The 28-day mortality rate (9.6 vs. 10%; p-value 1) was not different. CONCLUSIONS: There has been a different clinical spectrum of COVID-19 amongst KTR with similar mortality between the two waves at a large Indian transplant centre.

Successful management of dengue in renal transplant recipients: A retrospective cohort from a single center.

INTRODUCTION: The literature on dengue infection in renal transplant recipients has shown wide diversity in clinical presentation and outcome. The objective of this study was to report the clinical profile, short-term and long-term outcomes of dengue among renal transplant recipients. METHODS: A total of 59 post-transplant dengue suspected cases were admitted from July 2019 to April 2020 of which 31 had confirmed dengue infection. The clinical and laboratory profile of the confirmed dengue cases (n = 31) were compared with non-dengue cases (n = 28). RESULTS: Among the clinical and laboratory features retro-orbital pain, conjunctival redness, thrombocytopenia on admission, and absence of arthralgia were significantly associated with dengue compared to non-dengue cases. No mortality was observed in the dengue cases. Allograft dysfunction, acute rejection and graft losses were identified in 64.5% (n = 20), 6.4% (n = 2) and 6.4% (n = 2) dengue cases respectively. No rejection or graft losses were observed in 1-year follow-up. CONCLUSIONS: We report a differential clinical profile for dengue in transplant settings which will aid in the diagnosis. We also report successful management of dengue infection in renal transplant recipients with the majority having allograft dysfunction. A long-term follow-up of the cohort was uneventful.

Non-simultaneous kidney exchange cycles in resource-restricted countries without non-directed donation - a prospective single-center cohort study.

Recent reports suggest that bridge-donor reneging is rare (1.5%) in non-simultaneous kidney exchange chains. However, in developing countries, the non-directed donors who would be needed to initiate chains are unavailable, and furthermore, limited surgical space and resources restrain the feasibility of simultaneous kidney exchange cycles. Therefore, the aim of this study was to evaluate the bridge-donor reneging rate during non-simultaneous kidney exchange cycles (NSKEC) in a prospective single-center cohort study (n = 67). We describe the protocol used to prepare co-registered donor-recipient pairs for non-simultaneous surgeries, in an effort to minimize the reneging rate. In addition, in order to protect any recipients who might be left vulnerable by this arrangement, we proposed the use of standard criteria deceased-donor kidneys to rectify the injustice in the event of any bridge-donor reneging. We report 17 successful NSKEC resulting in 67 living-donor kidney transplants (LDKT) using 23 bridge-donors without donor renege and no intervening pairs became unavailable. We propose that NSKEC could increase LDKT, especially for difficult-to-match sensitized pairs (25 of our 67 pairs) in countries with limited transplantation resources. Our study confirms that NSKEC can be safely performed with careful patient-donor selection and non-anonymous kidney exchanges.

Long-term follow-up of SARS-CoV-2 recovered renal transplant recipients: A single-center experience from India.

INTRODUCTION: Follow-up studies of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in kidney transplant recipients (KTR) are scarcely reported. METHODS: We studied 142 hospitalized KTR for a median (interquartile range) follow-up of 9 (8-11) months who recovered from SARS-CoV-2 during May 2020 to Dec 2020. The outcomes were to assess persistent symptoms post-discharge; EuroQoL visual analogue score (EQ-VAS); EuroQoL 5-dimension score (E5-QD-5L) score and modified medical research dyspnea score (mMRC) at 1 month, 3-month, and beyond 6 months. Graft outcome was also analyzed. RESULTS: The age of the cohort was 43 (34-69) years and COVID-19 severity ranged from asymptomatic (4%), mild (50%), moderate (35%) to severe (12%). The most common persistent symptom was fatigue which significantly decreased in the follow-up (n = 45 [32.3] vs. 10 [7.4] vs. 4 [2.9]; p-value = 0.001) at 1-month, 3-month, and beyond 6 months respectively. Decrement in the mean (standard deviation) EQ-VAS score from baseline was also improved (28.6 [13] vs. 10.4 [12.5] vs. 7.5 [12.0]; p-value = 0.012). There was significant improvement in all EQ-5D-5L scores in follow-up. There was no deterioration in mMRC scores during the follow-up (n = 4, 3% vs. 7, 5% vs. 3, 2%; p-value = 0.86). Cases requiring oxygen had significantly poorer overall scores initially, but there was no difference at 6 months. All 10 graft losses had oxygen requirement and chronic graft dysfunction at baseline. CONCLUSION: Our initial assessment reports significant improvement in the quality of life in follow-up. The majority recovered from allograft dysfunction. Further research is warranted to study the full spectrum of follow-up.

Expanding donor pool by utilizing deceased donors with snake envenoming.

In India, the deceased kidney transplant program is still in its preliminary stage, and accepting deceased donors with snakebite is just a forward step to expand the donor pool. We report here the outcome of 8 successful renal transplantations from brain-dead donors who died from a neurotoxic snakebite. We accepted them as donors as they had no evidence of hemotoxic snakebite. 7 recipients did well. 1 died due to sepsis with a functioning graft. 1 required renal biopsy that showed acute tubular necrosis. 1 required re-exploration due to graft collection due to a surgical issue. Patient and graft survival in follow-up were similar to other matched deceased donors in our center. According to our experience, utilizing brain-dead donors who died from a neurotoxic snakebite is safe and may dramatically expand the donor pool especially in countries where death due to snakebite is high in numbers.

Enhanced recovery after surgery protocol enhances early postoperative recovery after pancreaticoduodenectomy.

BACKGROUND: Enhanced recovery after surgery (ERAS) protocol is a multimodal, multidisciplinary and evidence-based approach to reduce surgical stress and enhance recovery in the postoperative period. This study aimed to analyze the outcome of ERAS protocol in patients after pancreaticoduodenectomy (PD). METHODS: A total of 50 consecutive patients with pancreatic/periampullary cancer who underwent PD between January 2016 to August 2017 were included in the study. As per the institute ERAS protocol, nasogastric tube (NGT) was removed on postoperative day (POD) 1 if output was less than 200 mL and oral sips were allowed; oral liquids were allowed on POD2; semisolid diet by POD3; abdominal drain was removed on POD 4 if output was less than 100 mL with no evidence of postoperative pancreatic fistula (POPF); normal diet was allowed on POD5. Discharge criteria on POD6 were afebrile, tolerating oral normal diet, pain free and no surgery related complications (defined as per the ISGPS definitions). RESULTS: NGT was removed on POD1 in 45 (90%) patients, abdominal drain removed by POD4 in 41 (82%) and 43 (86%) patients were discharged on POD6. There was no 30-day postoperative mortality. Three (6%) patients had delayed gastric emptying (DGE). None had postoperative hemorrhage and POPF. Readmission rate was 8%. A significant relation was found between the length of hospital stay (LOS) with age (P < 0.05) and a marginal relation between LOS and postoperative albumin (P = 0.05). CONCLUSIONS: ERAS protocol can be safely followed in the perioperative care of patients who undergo PD. Early removal of NGT and allowing oral diet restore bowel function early. ERAS decreases the LOS and postoperative complications.

Upscaling of Helmholtz Equation Originating in Transmission through Metallic Gratings in Metamaterials.

We investigate the transmission properties of a metallic layer with narrow slits. We consider (time-harmonic) Maxwell's equations in the H-parallel case with a fixed incident wavelength. We denote η > 0 as the typical size of the complex structure and obtain the effective equations by letting η → 0. For metallic permittivities with negative real part, plasmonic waves can be excited on the surfaces of the slits. For the waves to be in resonance with the height of the metallic layer, the corresponding results can be perfect transmission through the layer.

Functional mechanisms of drought tolerance in subtropical maize (Zea mays L.) identified using genome-wide association mapping.

BACKGROUND: Earlier studies were focused on the genetics of temperate and tropical maize under drought. We identified genetic loci and their association with functional mechanisms in 240 accessions of subtropical maize using a high-density marker set under water stress. RESULTS: Out of 61 significant SNPs (11 were false-discovery-rate-corrected associations), identified across agronomic traits, models, and locations by subjecting the accessions to water stress at flowering stage, 48% were associated with drought-tolerant genes. Maize gene models revealed that SNPs mapped for agronomic traits were in fact associated with number of functional traits as follows: stomatal closure, 28; flowering, 15; root development, 5; detoxification, 4; and reduced water potential, 2. Interactions of these SNPS through the functional traits could lead to drought tolerance. The SNPs associated with ABA-dependent signalling pathways played a major role in the plant's response to stress by regulating a series of functions including flowering, root development, auxin metabolism, guard cell functions, and scavenging reactive oxygen species (ROS). ABA signalling genes regulate flowering through epigenetic changes in stress-responsive genes. ROS generated by ABA signalling are reduced by the interplay between ethylene, ABA, and detoxification signalling transductions. Integration of ABA-signalling genes with auxin-inducible genes regulates root development which in turn, maintains the water balance by regulating electrochemical gradient in plant. CONCLUSIONS: Several genes are directly or indirectly involved in the functioning of agronomic traits related to water stress. Genes involved in these crucial biological functions interacted significantly in order to maintain the primary as well as exclusive functions related to coping with water stress. SNPs associated with drought-tolerant genes involved in strategic biological functions will be useful to understand the mechanisms of drought tolerance in subtropical maize.

Editorial for Advanced Antennas for Wireless Communication Systems.

In recent years, there has been a significant expansion in wireless communication, evolving into a global network connecting billions of entities, including individuals and enterprises [...].

Metal-free carbon-based anode for electrochemical degradation of tetracycline and metronidazole in wastewater.

Degradation of antibiotics through electrocatalytic oxidation has recently been comprehended as a promising strategy in wastewater treatment. Herein, nitrogen and sulphur doped graphene oxide (N,S-rGO) nanosheets were synthesized and employed as metal-free anodic material for electrochemical degradation of antibiotics, viz. metronidazole (MNZ) and tetracycline (TC). The synthesized anodic material was characterized using various spectral techniques and further the electrochemical behaviour of N,S-rGO was thoroughly examined. Thereafter, the N,S-rGO material was then employed as the anode material towards the electrocatalytic degradation of antibiotics. Parameters such as initial concentration of the antibiotics and current densities were varied and their effect towards the degradation of MNZ and TC were probed. Notably, the N,S-rGO based anode has shown impressive removal efficiency of 99% and 98.5%, after 120 min of reaction time for MNZ and TC, respectively, under optimized conditions. The obtained results including the kinetic parameters, removal efficiency and electrical efficiency ensure that the prepared anodic material has huge prospective towards real-time application for removal of antibiotics from water.

Act Together and Act Now to Overcome Gender Disparity in Organ Transplantation.

Gender disparity refers to the unequal treatment or a perception of individuals based on their gender and arises from differences in socially constructed gender roles. In the field of transplantation, gender inequality arises at different stages, affecting access to medical care, donation practices, and posttransplant followup care. Gender disparity in transplantation is not limited to any geographic region but is thought to be more prevalent in developing nations. An unusually high number of female donations with relatively fewer female recipients is not only attributable to the low economy but a congregation of medical, social, cultural, and psychological factors. Gender disparities can also be shown in transplant-related professional societies. This review highlights the complexities of spousal donation and vulnerability of women, especially in the developing world. There is a growing need to further modify transplant policies to tackle gender disparities, especially in living related donation. Systematic research in the context of gender-related concerns in transplantation will further aid in understanding the complexities and formulating policies for eliminating gender disparities. Gender disparity is a global problem and not merely limited to transplantation.

Development of metasurface based hyperthermia lens applicator for heating of cancerous tissues.

Numerous designs and methods have been examined to improve penetration depth (PD), but there is a need for research to explore the potential increase in PD through uniform heating, a compact applicator, and low input power. This paper presents metasurface based hyperthermia lens applicator with water bolus for uniform heating of cancerous tissues. The proposed applicator consists of a stacked spiral antenna and a spiral-shaped frequency selective surface as a superstrate. The spiral antenna and superstrate are optimized on a low cost FR4 substrate having a size of 32 × 32 × 3.27mm3 and 10 × 10 × 1.6mm3 (size of the unit cell), respectively. The proposed applicator is simulated with heterogeneous phantom (skin, fat, and muscle layers) and with the Gustav voxel model with and without a water bolus layer. The number of unit cells in the superstrate is optimized to direct the maximum energy toward the tumor location. The performance study of the applicator is carried out in terms of specific absorption rate, PD, and effective field size. Further, thermal analysis is carried out with 1.9 W of input power at the antenna port, and the highest 44.7 °C temperature rise is obtained. The cancerous tissue's (tumor) surrounding temperature is between 41 and 45 °C, which is adequate for efficient hyperthermia treatment. Finally, the proposed metasurface hyperthermia lens applicator is fabricated and experimentally validated in a mimicked phantom's presence. Supplementary Information: The online version contains supplementary material available at 10.1007/s13534-023-00300-z.

Physical analysis of aspirin in different phases and states using density functional theory.

This study analyzed the aspirin molecule (C9H8O4) using Density Functional Theory (DFT) on Gaussian 09W software. First, the structure of aspirin was optimized using the DFT method with the B3LYP functional and the 6-311+G (d,p) basis set. A global reactivity study was employed to understand the reactivity of aspirin in gas and solvent water for both anion and neutral states. To understand the involvement of orbitals in chemical stability and electron conductivity, we calculated the HOMO-LUMO. The thermodynamic function of a molecule was understood using thermochemistry. Molecular Electrostatic Potential (MEP) was employed to understand the physiochemical properties of aspirin. We observed the Mulliken atomic charge to calculate the atomic charge of aspirin. Finally, the title molecule's UV-Vis, FTIR, and Raman spectra are analyzed and compared with the experimental data.

Prognostic role of PD-L1 expression in head and neck squamous cell carcinoma: An institutional experience from India.

BACKGROUND: Squamous cell carcinoma accounts for > 90% of Head and neck cancers and has a poor 5-year survival rate of only 50%. Immunosuppressive agents like PD-L1 inhibitors have been found to improve survival in many tumour types, including advanced/recurrent head and neck squamous cell carcinoma (HNSCC). The PD-L1 expression in this tumour can also predict clinical outcome. However, this fact still remains to be proven. AIM: The aim was to study the expression of PD-L1 in HNSCC, correlate with clinicopathological parameters and outcome. MATERIAL AND METHOD: This prospective study was conducted between March 2021 to June 2023 in department of Pathology of a tertiary care centre located in northern India. A total of 65 histologically confirmed cases of HNSCC were included. Expression of PD-L1 was determined by immunohistochemistry. The combined positive (CPS) and tumour proportion (TP) scores were calculated. The results were correlated with clinicopathological parameters and outcome using appropriate statistical tools. RESULTS: Considering CPS, 42 (64.6%) cases showed expression of PD-L1. A high score of ≥ 20% was seen in 10 cases (15.4%). PD-L1 expression did not correlate with any of the clinical parameters including age, gender, addiction, site, TNM stage and HPV status. Conventional HNSCC had significantly higher expression of PD-L1. The cases with positive PD-L1 expression had a higher mean survival and a lower mortality, but the difference was not statistically significant. CONCLUSION: PD-L1 expression is more likely to be seen in conventional HNSCC histomorphology. PD-L1 expression is a predictor of better prognosis in HNSCC.