Effect of Age of Transfused Red Blood Cell Units on Clinical Outcomes in Critically Ill Patients.

Anemia in critically ill patients requires red cell transfusions to increase oxygen delivery and prevent deleterious outcomes. The primary objective of the present study was to determine the effect of storage age of transfused red cells on 30-day mortality in critically ill patients, with secondary objectives of determining the effect on length of stay, organ failure, and adverse transfusion reactions. This prospective study was conducted on patients admitted to the intensive care unit after obtaining approval from institutional ethics committee. Patients were randomized to transfusion with packed red blood cells (PRBC) with age of collection either ≤ 14 days (Group 1) or > 14 days (Group 2). APACHE II scores were calculated at admission. Patients were followed up for primary outcome of 30-day mortality, and secondary outcomes including length of stay, infections, organ dysfunction, and adverse transfusion reactions. The 30-day mortality was 20% in Group 1 and 28% in Group 2 (p = 0.508). The mean storage duration of PRBC in Group 1 versus Group 2 was 8.48 days versus 21.43 days (p < 0.001). There was no significant difference in total number of PRBC transfusions, donor exposures, hemoglobin and hematocrit increment, adverse transfusion reactions, length of stay and organ dysfunction scores between the two groups. Transfusion of packed red cells of less than 14 days showed no benefit over red cells stored more than 14 days in terms of 30-day mortality, length of stay and infections in critically ill patients, however studies with larger sample size and longer follow up are recommended.

DEL phenotype in RhD-negative North Indian blood donors.

BACKGROUND: Rh-DEL type is not detected on routine serology and requires specialized adsorption elution methods which are laborious. Identifying the DEL phenotype in blood donors is important to prevent alloimmunization in transfusion recipients. The present study aimed to determine the frequency of DEL phenotype in RhD-negative North Indian blood donors and correlate the results with Rh Cc/Ee phenotype. MATERIALS AND METHODS: In this prospective descriptive cross-sectional study, a total of 205 blood donors with historic blood group RhD-negative were enrolled. All samples were subjected to blood grouping using a fully automated immunohematology analyzer and samples that typed as RhD negative by two different anti-D antisera were tested for Weak D. Weak D-negative samples were subjected to adsorption and elution for DEL phenotype. All samples were also tested for extended Rh phenotype for C/c and E/e antigens. RESULTS: Of the total 11934 donors during the study, 6.2% (n = 743) donors were RhD negative. Of the 205 donors enrolled in the study, two donor samples were serologically weak D positive. None of the remaining 203 donors tested positive for the DEL phenotype. The extended Rh phenotype performed for these donors showed that 6.83% (n = 14) donors were positive for RhC antigen and 1.46% (n = 3) were positive for Rh E antigen. Both weak D-positive donors were also positive for the Rh C antigen. CONCLUSION: The prevalence of DEL phenotype is low in the Indian population and studies with larger sample sizes are required to determine the effectiveness of routine C/E typing as a strategy to identify DEL-positive individuals.

Acute global longitudinal strain evaluation in patients with subacute to chronic chest pain: A pilot, observational study.

Background: Global longitudinal strain (GLS) imaging is a multifaceted modality that has been utilized in various fields of clinical cardiology in the recent past; however, its implementation for the assessment of ischemia has been limited. Objectives: This study aimed to document the functional changes in GLS secondary to acute myocardial ischemia in patients with chronic chest pain. Methods: In this unblinded, single-center, investigator-initiated, prospective pilot study, the functional changes in GLS at baseline, during, and immediately following coronary percutaneous intervention were monitored in 10 ambulatory patients who underwent elective catheterization. The exclusion criteria included a low ejection fraction, or a history of chemoradiation, myopathy, and congenital heart disease. Results: The average GLS at baseline, during the balloon intervention (BI), and 1-2 min after BI was -15.4 % ±â€¯3.3 %, -10.2 % ±â€¯3.6 %, and -16.1 % ±â€¯4.2 %, respectively. The average GLS decreased significantly by 5.1 % (95 % CI, -7.9 % to -2.3; P = 0.0013) from baseline to BI, increased by 6.3 % (95 % CI, 3.7 % to 8.9 %; P < 0.001) from BI to immediately post-BI, and increased by 0.7 % from baseline to post-BI (95 % CI, -0.4 % to 2.7 %; P = 0.161). Conclusion: Patients undergoing BI showed a significant decrease in the average GLS within 1-2 min of BI, with GLS returning to baseline subsequently, clearly demonstrating the efficacy of the modality and the clinical significance of data obtained. These functional changes replicate cardiac perfusion to the segments supplied by respective vessels and its effect with reperfusion or ballooning. The slight increase in GLS from baseline to post-intervention was not statistically significant, which could be attributed to the confounding factors. Analyzing our data, we can safely conclude that GLS is potentially a sensitive, temporal, and quantitative tool for identifying patients with acute ischemia with its limitations and need for further perfection of this modality. Therefore, GLS assessments on 2D echo can be used for risk stratification of patients with subacute to chronic chest pain concerning for ischemia in addition to EKG, troponins and other data obtained by non-invasive testing and evaluation.

Targeting T regulatory (Treg) cells in immunotherapy-resistant cancers.

Primary or secondary (i.e., acquired) resistance is a common occurrence in cancer patients and is often associated with high numbers of T regulatory (Treg) cells (CD4+CD25+FOXP3+). The approval of ipilimumab and the development of similar pharmacological agents targeting cell surface proteins on Treg cells demonstrates that such intervention may overcome resistance in cancer patients. Hence, the clinical development and subsequent approval of Cytotoxic T Lymphocyte Antigen-4 (CTLA-4) targeting agents can serve as a prototype for similar agents. Such new agents aspire to be highly specific and have a reduced toxicity profile while increasing effector T cell function or effector T/T regulatory (Teff/Treg) ratio. While clinical development with large molecules has shown the greatest advancement, small molecule inhibitors that target immunomodulation are increasingly entering early clinical investigation. These new small molecule inhibitors often target specific intracellular signaling pathways [e.g., phosphoinositide-3-kinase delta (PI3K-δ)] that play an important role in regulating the function of Treg cells. This review will summarize the lessons currently applied to develop novel clinical agents that target Treg cells.

Evaluation of chemiluminescence immunoassay as a screening test for syphilis on blood donor samples.

BACKGROUND AND OBJECTIVE: Global re-emergence of syphilis among blood donors necessitates novel diagnostic and prevention approaches that encourage timely intervention. Thus, the present study was planned to evaluate the efficiency of Chemiluminescence immunoassay (CLIA) as a screening test for syphilis. MATERIAL AND METHODS: This prospective cross-sectional observational study was conducted from October 2021 to September 2022. A total of 344 donors were enrolled by purposive sampling method, including additional 16 donors who were reactive by the Rapid plasma reagin test (RPR) during the study period. Data from three screening tests - RPR test, Treponema pallidum haemagglutination assay (TPHA) and CLIA for 360 blood donors were analysed. TPHA was considered the gold standard test. RESULTS: Of the total 360 samples tested, 21 (5.8 %) were reactive by the RPR test. Of these 21 RPR reactive samples, 19 (90.5 %) were reactive by both TPHA and CLIA, while 2 (9.5 %) RPR reactive samples were non-reactive by both TPHA and CLIA. Of the remaining 339 RPR non-reactive samples, 1 (0.3 %) sample was reactive by both TPHA and CLIA, and 1 (0.3 %) was reactive by CLIA alone. CLIA was found to have sensitivity and specificity of 100 % and 99.7 % and positive predictive value (PPV) and negative predictive values (NPV) of 95.2 % and 100 % respectively, while it was 95 %, 99.4 %, 90 %, and 99.7 %, respectively, with the RPR test. CONCLUSION: CLIA was found to have a higher sensitivity, specificity, PPV and NPV than the RPR test. Thus, CLIA can be an acceptable alternative for syphilis screening in blood donors.

Physiological and psychological stress response of blood donors during the blood donation process.

BACKGROUND AND OBJECTIVES: Blood donation can be a potentially stressful event, leading to the activation of an acute stress response. Knowing and identifying potential stressors could help in optimizing the donation experience. The present study aimed to measure the physiological and psychological stress changes before, during and after blood donation. MATERIALS AND METHODS: Physiological and psychological stress response was assessed in 70 blood donors. To evaluate physiological stress response, pulse rate, respiratory rate, blood pressure (BP), beat-to-beat BP and lead II electrocardiogram were recorded. Baroreflex sensitivity was calculated using the available software. Psychological stress response was assessed using the State-Trait Anxiety Inventory scale. RESULTS: A significant increase in systolic blood pressure, diastolic blood pressure and mean arterial pressure was observed in the pre-donation period (p < 0.001). Among the time-domain parameters, SDSD (standard deviation of differences between adjacent respiratory rate intervals) and RMSSD (root mean square of the successive differences) were significantly lower during the post-donation period (p < 0.005, p < 0.007, respectively). Among the frequency-domain parameters, LF nu (relative power of the low-frequency band in normalized units), HF nu (relative power of the high-frequency band in normalized units) and LF% (relative power of the low-frequency band in percentage) were significantly lower before donation compared to during donation (p < 0.001, p < 0.001 and p < 0.012, respectively). LF nu, LF% and LF/HF ratio were also significantly lower during donation compared to after donation (p < 0.05, p < 0.016 and p < 0.042, respectively). Baroreflex sensitivity was also statistically higher during the pre-donation period. State score was significantly higher among the blood donors during the pre-donation period. CONCLUSION: Physiological and psychological stress is experienced by blood donors during the pre-donation period. A pre-donation informative conversation should be carried out with each blood donor and potential stressors should be identified in each.

Association of blood donor characteristics and in vitro haemolysis of packed red blood cell concentrates during storage.

BACKGROUND AND OBJECTIVES: Blood donor variability can affect the storage properties of packed red blood cells (PRBCs). This study aimed to determine the association of donor characteristics with in vitro storage haemolysis of PRBCs. MATERIALS AND METHODS: In the prospective observational study, a total of 109 whole blood donors were enrolled using the purposive sampling method. A pre-donation sample was collected for haemoglobin (Hb) and serum uric acid (UA) levels. PRBC aliquots were tested for potassium, lactate dehydrogenase (LDH), Hb, haematocrit, plasma Hb and haemolysis on days 1, 21 and 35 of storage. The association of these parameters with donor age, sex, donation status, dietary pattern and body mass index was determined. RESULTS: Mean haemolysis was significantly higher in PRBCs from donors with UA levels ≤6 mg/dL than donors with UA levels >6 mg/dL on day 35 of storage (0.22 ± 0.11 vs. 0.18 ± 0.07, p = 0.03). Median plasma Hb (mg/L) was significantly higher in PRBCs from first-time donors on day 21 (586 vs. 509, p = 0.05) and day 35 (1507 vs. 1358, p = 0.02) of storage in comparison to frequent donors. Significantly higher mean potassium (p = 0.04 day 1; p = 0.02 day 21) and median LDH values (p = 0.02 day 1, p = 0.05 day 21) were observed in PRBCs from male donors. A statistically significant positive association was observed between donor UA and LDH levels of PRBCs on day 35 of storage (ß coefficient: 715.52, p-value: 0.003) on multiple regression analysis. CONCLUSION: In vitro haemolysis of PRBCs is affected by blood donor characteristics.

Association of blood donor characteristics with hemoglobin content in leukoreduced packed red blood cells.

BACKGROUND AND OBJECTIVES: A complex relationship exists between donor characteristics and red blood cell quality which remains partly explored. The present study aimed to determine the correlation of donor characteristics with the hemoglobin (Hb) content of leukoreduced packed red blood cells (PRBC). MATERIALS AND METHODS: This prospective cross-sectional study was conducted on 100 blood donors. A pre-donation sample was collected for hemoglobin and hematocrit estimation. Whole blood was collected in quintuple blood bags and packed red cells were prepared. Sample from each packed red cell unit was estimated for hemoglobin and hematocrit. The volume, total Hb, actual total Hb, volume and Hb lost during processing, mathematical total Hb and hematocrit of each PRBC unit was calculated using formulas. The donor characteristics were analysed for correlation with Hb content of PRBC. RESULTS: The mean age of the 100 donors enrolled in the study was 36.3 ± 9.9 years. Majority of the donors were vegetarian, non-alcoholic, non-smokers, and had a pre-donation hemoglobin level of more than 14 g/dl. The mean pre-donation Hb of the donors was 14.8 ± 1.5 g/dl. There was a strong positive correlation of donor pre-donation hemoglobin with total Hb (r = 1.000, p = 0.000), actual Hb (r = 0.518, p = 0.000) and mathematical hemoglobin (r = 0.951, p = 0.000) using the Pearson correlation test. A strong positive correlation was observed between the total and actual hemoglobin (r = 0.518, p = 0.000) of the units. There was no association of other donor characteristics with Hb content of leukoreduced PRBC. CONCLUSION: Donor pre-donation hemoglobin showed a strong positive correlation with the actual hemoglobin content of leukoreduced packed red blood cells.

Size economy and first hyperpolarizability: synthesis and nonlinear optical behavior of ferrocene-based donor-acceptor chromophores lacking π-linkers.

The question of size economy in the design of chromophores for nonlinear optics is addressed in this investigation. We have synthesized directly linked donor-acceptor dyads, which lack a π-conjugated linker, the presence of which is usually considered obligatory in materials designed for nonlinear optics. Correlating linear optical data, electrochemical data, computational data and hyper Rayleigh scattering (HRS) data on ferrocene (Fc) based dyads, we demonstrate that the first hyperpolarizability of such size economical chromophores is significantly better compared to that of Fc based, traditional, larger, donor-π-acceptor chromophores. Arguably, a larger π-conjugated linker decreases the electronic communication between the donor and the acceptor and weakens the intramolecular charge transfer in such chromophores.

Bis-cyanostilbene based fluorescent materials: A rational design of AIE active probe for hypochlorite sensing.

In the present investigation cyanostilbene based molecular probes, PCS and PCO, bearing N,N-dimethylthiocarbamate and N,N-dimethylcarbamoyal groups, respectively, have been synthesised. These probes exhibit AIEE activity in their aggregated state in the mixed solvent system of THF: H2O by way of turning on their emission, which has also been observed in powder, neat thin films and hybrid polymer films. While the probe PCO is silent to ClO-, PCS exhibits a significant response towards ClO- rationalised on the basis of HOCl specific oxidation of thiocarbamate, which is also extended to detect ClO- in water samples. Additionally, applicability of the test strips of PCS for rapid on-site detection of ClO- has been demonstrated. The experimental results are supplemented by the theoretical calculations wherever possible.

Association of blood donor characteristics with in vitro platelet storage properties.

BACKGROUND AND OBJECTIVE: The study was planned to determine the association of blood donor characteristics with in vitro quality of platelets. MATERIAL AND METHODS: In the prospective observational study, a total of 85 male whole blood donors in the age group of 18-30 and 45-65 years were enrolled using purposive sampling method. Serum total cholesterol, glycosylated hemoglobin (HbA1c), and LDH levels were performed on donor pre-donation sample. Buffy coat platelet concentrates were prepared from 450 mL quadruple blood bags. Samples from platelets were taken on day one and five of storage and biochemical properties were observed. RESULTS: Median MPV was higher in platelets from older blood donors on day five (9.8 vs 9.4, p = 0.037). Median LDH levels were also higher in platelets on day one and five from older donors (Day one: 204.5 vs 147, p = <0.000; day five: 278 vs 224, p = 0.001 respectively). Platelets from donors with high HbA1c levels had lower median pH (Day one: 7.31 vs 7.37, p = 0.024) and higher median glucose levels on day one of storage (Day one: 358 vs 311, p = 0.001). Higher median lactate levels throughout the storage period were also seen in platelets from donors with higher HbA1c levels (Day one: 7 vs 5.7, p = 0.037; Day five: 16 vs 12.2, p = 0.032). Glucose consumption (108 vs 66, p = 0.025) and lactate production (9 vs 6.4, p = 0.019) was higher in platelets from donors with higher HbA1c levels. CONCLUSION: In vitro platelet storage properties are affected by blood donor characteristics.

Effect of double dose plateletpheresis on target yield and donor platelet recovery

Abstract Introduction The demand for apheresis platelets has increased in the recent past and the shrinking donor pool has shifted the trend to collection of double-dose or higher yield of platelets. Objective The present study aimed to determine the effect of double-dose plateletpheresis on the target yield and donor platelet recovery. Methods The study was conducted on 100 healthy plateletpheresis donors, 50 of whom were in the study group, which underwent double-dose plateletpheresis (DDP), and 50 of whom were in the control group for single-donor plateletpheresis. Pre- and post-procedure samples of donors were subjected to a complete blood count. The DDP product was sampled for platelet yield and then split into two parts. Platelet yield, collection efficiency, collection rate, recruitment factor and donor platelet loss were calculated. Results The mean platelet yield in the SDP was 4.09 ± 1.15 × 1011 and in the DDP, 5.93 ± 1.04 × 1011. There was a significant correlation between the pre-donation platelet count and platelet yield. The total of platelets processed for the SDP were 5.42 ± 1.08 × 1011 and for the DDP, 7.94 ± 0.77 × 1011. The collection efficiency was 71.93 ± 25.14% in the SDP and 72.94 ± 16.28% in the DDP, while the collection rates were 0.78 × 1011 and 0.94 × 1011 per minute, respectively. The average recruitment factor observed was 0.98 in the SDP, while it was 0.99 in the DDP. The mean platelet loss observed in the SDP was 35.55 ± 8.53% and in the DDP, 37.76 ± 8.65%. Conclusion The double-dose plateletpheresis supplements the platelet inventory in developing countries where the apheresis donor pool is limited. It is prudent to ensure stringent donor selection criteria for donors donating high-yield platelet products, thus enhancing donor safety and retention.

Recurrent Subclavian Steal Syndrome: A Novel Case of Vasculopathy.

Subclavian steal syndrome (SSS) refers to the phenomenon of retrograde flow in an ipsilateral branch of the subclavian artery due to hemodynamically significant stenosis or occlusion of the ipsilateral proximal subclavian artery. While SSS is usually asymptomatic, it can manifest as vertebrobasilar insufficiency (VBI), ischemia of the affected extremity, or cardiac angina when an internal mammary artery (IMA) is used as a bypass graft. The underlying etiology is most often atherosclerosis but can include Takayasu arteritis, thoracic outlet syndrome, cervical rib, and stenosis secondary to surgical repair of aortic coarctation or tetralogy of Fallot. There are several case reports describing unique presentations of SSS as well as limited reports of double SSS, where the brachiocephalic steno-occlusive disease causes flow reversal in both the ipsilateral vertebral and carotid arteries. We report herein the first documented case, to our knowledge, of a patient with SSS previously treated with left subclavian artery stenting and left common carotid-subclavian bypass who developed recurrent SSS in conjunction with orthostatic cerebral hypoperfusion syndrome (OCHOS) secondary to severe vasculopathy. She presented with recurrent, paroxysmal vertigo and near-syncope associated with left upper extremity paresthesias that would only abate with sitting in the context of left subclavian artery stent restenosis and occlusion of her left common carotid-subclavian bypass graft. Interestingly, her initial presentation entailed retrograde flow from the left vertebral artery to the left subclavian artery, classic for SSS, but recurrence of her SSS involved retrograde flow from the left common carotid artery to the left subclavian artery, a phenomenon which has also not been described in the literature to our knowledge. As her symptoms of VBI appeared to be triggered by standing and not left arm movement, they were considered to be primarily secondary to OCHOS. Consequently, her primary treatment was to increase salt and fluid intake and thus increase intravascular volume for improved cerebral perfusion as she was not deemed to be a suitable candidate for regrafting of the left subclavian artery.

Julolidine-hydrazone based chemosensor for detection of Zn2+: Fluorescent in-situ formed Zn2+ complex discriminates PPi from ADP and ATP.

In the present investigation, we have designed and synthesised Zn2+ sensitive Julolidine-hydrazone (JSB) based chemosensor, which crystallised in a monoclinic crystal system with P21/c space group. The bare JSB was nonemissive, but in the presence of Zn2+ ions in solution it showed emission, ascribed to the chelation enhanced emission process, which is also utilised to detect Zn2+ in water samples. Comparing the chromaticity coordinates deduced from the emission colors of the JSB-Zn2+ in solution, powder and hybrid polymer thin film, using CIE (Commission Internationale de I'Eclairage 1931) chromaticity diagram, it was found that compared to the emission of the solution, the emission of the powder was red shifted, while that of the thin film was blue shifted. Further, the sensing of Zn2+ showed reversibility in the presence of pyrophosphate (PPi), which allowed quantification of PPi. Interestingly, in addition to the detection of PPi using the in-situ formed JSB-Zn2+ complex, the process was selective and discriminated PPi from ADP and ATP. The detection of PPi was rationalized via a decomplexation reaction, and translated in the construction of INHIBIT logic gate. Additionally, the possible use of the JSB coated sensor paper for the on-site detection of Zn2+ and subsequent JSB-Zn2+ complex for PPi ions has been demonstrated. The experimental results showed good correlation with the theoretical calculations wherever possible.

Effect of double dose plateletpheresis on target yield and donor platelet recovery.

INTRODUCTION: The demand for apheresis platelets has increased in the recent past and the shrinking donor pool has shifted the trend to collection of double-dose or higher yield of platelets. OBJECTIVE: The present study aimed to determine the effect of double-dose plateletpheresis on the target yield and donor platelet recovery. METHODS: The study was conducted on 100 healthy plateletpheresis donors, 50 of whom were in the study group, which underwent double-dose plateletpheresis (DDP), and 50 of whom were in the control group for single-donor plateletpheresis. Pre- and post-procedure samples of donors were subjected to a complete blood count. The DDP product was sampled for platelet yield and then split into two parts. Platelet yield, collection efficiency, collection rate, recruitment factor and donor platelet loss were calculated. RESULTS: The mean platelet yield in the SDP was 4.09 ±â€¯1.15 × 1011 and in the DDP, 5.93 ±â€¯1.04 × 1011. There was a significant correlation between the pre-donation platelet count and platelet yield. The total of platelets processed for the SDP were 5.42 ±â€¯1.08 × 1011 and for the DDP, 7.94 ±â€¯0.77 × 1011. The collection efficiency was 71.93 ±â€¯25.14% in the SDP and 72.94 ±â€¯16.28% in the DDP, while the collection rates were 0.78 × 1011 and 0.94 × 1011 per minute, respectively. The average recruitment factor observed was 0.98 in the SDP, while it was 0.99 in the DDP. The mean platelet loss observed in the SDP was 35.55 ± 8.53% and in the DDP, 37.76 ± 8.65%. CONCLUSION: The double-dose plateletpheresis supplements the platelet inventory in developing countries where the apheresis donor pool is limited. It is prudent to ensure stringent donor selection criteria for donors donating high-yield platelet products, thus enhancing donor safety and retention.

Revisiting the impact of serial therapeutic phlebotomy in polycythaemia on laboratory and clinical parameters using a fixed interval and fixed volume protocol.

OBJECTIVES: Therapeutic phlebotomy allows for a controlled and gradual decrease in red cell mass leading to improved blood flow and symptomatic relief in polycythaemia. The present study was aimed to determine the impact of serial fixed volume and fixed interval therapeutic phlebotomy protocol on the laboratory and clinical parameters in patients of polycythaemia. MATERIAL AND METHODS: This prospective longitudinal study was conducted over 18 months. The desired haematocrit for polycythemia vera and secondary polycythemia was 45% and 52% respectively. A fixed volume of 350 ml phlebotomy was performed every-three days till the achievement of desired haematocrit. Complete blood count was performed before and after each procedure and iron studies were done at the time of enrolment and after the achievement of desired haematocrit. Post-procedure symptomatic relief was assessed by a 10-point visual analogue scale (VAS). RESULTS: Of the 29 patients enrolled in the study, 3 patients were lost to follow up and data of 26 patients was analyzed. Mean Hb declined from 17.84 ± 1.88 gdL-1 to 14.67 ± 1.14 gdL-1 (p < 0.001) and mean haematocrit decreased from a baseline of 57.11 ± 5.47% to 46.27 ± 3.763% (p < 0.001) upon achievement of desired haematocrit. There was a significant decline in serum iron from the baseline of 132.85 ± 94.136 µg dL-1 to 69.41 ± 58.643 µg dL-1 at desired haematocrit. A significant change in VAS score of almost all clinical parameters was observed. Post phlebotomy hematocrit correlated negatively with the number of procedures (p = 0.015). CONCLUSION: Our protocol yielded rapid and marked improvement in patients of primary and secondary polycythemia with minimal adverse events and significant amelioration of clinical parameters.

Exploring the unseen effect of COVID 19 pandemic on blood transfusion services in a tertiary care centre.

BACKGROUND: The coronavirus pandemic confronted blood transfusion services with major challenges. The present study was conducted to explore the effect of the COVID-19 pandemic on blood transfusion services including seroprevalence of transfusion-transmitted infections. MATERIAL AND METHODS: A retrospective cross-sectional study was conducted and data on blood donation, utilization, camps, plateletpheresis and seroprevalence of transfusion-transmitted infections (TTI) was retrieved from software from March to September 2020 and 2021 and compared with corresponding time periods of three preceding non-pandemic years. RESULTS: There was a decline of 53.79% and 34.4% in blood donations in 2020 and 2021 respectively with a significant reduction in voluntary donations from 91.8% in the pre-pandemic period to 72.2% in 2020 and 77.7% in 2021. Replacement donors increased by 60.81% and 72.89% in 2020 and 2021 respectively. There was a decline of 48.4% in the number of plateletpheresis procedures in 2020 which increased in 2021 during the dengue outbreak. The decline in total blood donations and issue of packed red blood cells was statistically significant but supply and demand were balanced with no deficit. TTI seroprevalence increased from 1.01% to 1.49%(p<0.001) and 1.51%(p<0.001) in 2020 and 2021 respectively. Replacement donors showed a significantly higher TTI prevalence as compared to voluntary donors(p<0.001). A significant increase in prevalence was observed for Syphilis (0.4%) in 2020 and HBsAg (0.54%), HCV(0.63%) and syphilis (0.25%) in 2021. CONCLUSION: The potential consequences of the COVID-19 pandemic on blood safety cannot be undermined. Developing a strong database of regular voluntary donors can be instrumental in dealing with future waves and surges in infections.

Julolidine based red emitting ESIPT/AIE active material showing luminescence beyond excimer emission: An "on-off" emission response to Cu2.

A new julolidine-fluorene based excited state intramolecular proton transfer (ESIPT)/aggregate induced emission (AIE) active Schiff-base (JDF) has been synthesized and evaluated for its photophysical properties in solution and aggregated/solid states. The correlation between the emission behavior and the solid state crystal packing structure revealed the interplay of ESIPT coupled excimer reaction occurring in the solid state, which is one of the rare examples reported so far. For a comprehensive comparison, we synthesized a non-ESIPT methyl derivative (JDF-Me) of JDF capable of showing excimer emission only in the solid state. Further, JDF exhibits normal as well as keto emission in solution, upon addition of water, its poor solvent, that promotes aggregation, the fluorescence emission shows the preponderance of the excimer band in the low energy region. It was also interesting to note that in the solid state (thin films), JDF shows emission beyond the excimer emission, which is wavelength dependent. This is attributed to the formation of diverse clusters leading to the extended delocalization beyond excimers, and represents a clustering-triggered emission ascribing bright red color to the solid JDF. Such mélange of emission characteristics of JDF are responsible for the multicolor emission covering a broad range of electromagnetic spectrum, which is demonstrated by the confocal microscopy images of the JDF recorded in different states. Further, in its aggregated state, JDF recognized Cu2+ ions, selectively, manifested in the form of emission quenching via the interaction of Cu2+ ions with the oxygen and nitrogen atoms of JDF inhibiting the excimer formation.

Analyte Detection: A Decade of Progress in the Development of Optical/Fluorescent Sensing Probes.

The development of selective and sensitive chemical sensors capable of detecting metal ions, anions, neutral species, explosives and hazardous substances, selectively and sensitively has attracted considerable interest of various research groups. The presence of such analytes within the permissible limits is often beneficial, but the excess amounts may lead to lethal effects to both the environment as well as the living organisms. Owing to the toxicity of the heavy metal ions, toxic anions and nitro-aromatics which are main constituents of explosives, the timely detection of these materials is most desirable to ensure safety and security of the mankind. In this personal account, we present several classes of molecular sensors that were specifically designed in our lab during the past decade for detecting several species in solutions, solid state as well as biological media. Modulation of the optical properties in response to the presence of guest species, led to selective and sensitive detection protocols, and was supported by the theoretical studies wherever possible. We have also extended the application of some of these probes for the on-site detection of analytes by developing the paper strips, glass slides and even the wool and cotton fabrics loaded with probes. One such development represents detection of palladium in human urine and blood samples collected from clinical samples. Additionally, the sensing events in some cases have successfully been reproduced in the live cancer cells. Based on the ease and cost-effective synthesis of the molecular probes, we hope that this account shall provide significant information to researchers in understanding the structure dependent sensing capabilities of the molecular probes.

Synthesis and Nonlinear Optical Behavior of Thermally Stable Chromophores Based on 9,9-Dimethyl-9H-fluoren-2-amine: Improving Intrinsic Hyperpolarizability through Modulation of "Push-Pull".

Improvement in the first hyperpolarizability (ßHRS) as well as intrinsic hyperpolarizability (ßint) of chromophores based on 9,9-dimethyl-9H-fluoren-2-amine through modulation of the conjugation pathway is described. A series of six novel chromophores with "linear" conjugation showed significant enhancement of ßHRS as well as ßint compared to the counterparts lacking a "linear" conjugation but having an identical combination of donor, acceptor, and the intervening π-conjugated linker. The hyperpolarizability (ßHRS as well as ßint) values of the new series measured using hyper-Rayleigh scattering exceeded the apparent limit set by the latter set of fluorene-based chromophores. The experimental results are analyzed and interpreted in the context of linear optical properties, single-crystal X-ray analysis, electrochemistry, etc. and corroborated by theoretical studies. We find that modulation of the "push-pull" of the conjugation pathway in these donor-acceptor chromophores compares favourably with the corresponding changes in the optical gaps, transition dipole moments, and dipole moment difference between the ground and excited states.