How do DEI initiatives impact STEMM, and why do we still need them?

The number of diversity, equity, and inclusion (DEI) initiatives in science, technology, engineering, mathematics, and medicine (STEMM) have grown over the last few years. We asked several Black scientists what impact they have and why STEMM still needs them. They answer these questions and describe how DEI initiatives should evolve.

Prevalence of anemia and associated factors among pregnant women at Hargeisa Group Hospital, Somaliland.

BACKGROUND: Anemia remains a major global public health issue, affecting around 24.8% of the world's population in both developing and developed countries. Pregnant women in developing countries are particularly susceptible, with 38.2% affected worldwide. Anemia is also a major contributor to maternal mortality, with 510,000 maternal deaths globally, of which 20% occur in developing countries and are related to anemia. Iron deficiency anemia is the most prevalent form, impacting 1.3 to 2.2 billion individuals, with 50% being women of reproductive age. AIM: This study aimed to assess the prevalence and associated factors of anemia in pregnant women attending antenatal care (ANC) at Hargeisa Group Hospital (HGH), Somaliland. METHODS: A cross-sectional study included 360 pregnant women, who sought ANC at HGH from July 15 to August 6, 2023. The study subjects were selected using systematic random sampling. Data were collected through structured questionnaires and participants' current medical charts, including hemoglobin levels. Data analysis was performed using SPSS software (version 20). RESULTS: The study revealed an overall prevalence of anemia among pregnant women at 50.6% (95% CI: 45.40 - 55.72%). Anemia severity was categorized as mild (33.0%), moderate (54.9%), and severe (12.1%). Factors statistically associated with anemia included gestational age in the third trimester (AOR = 3.248, 95% CI: 1.491-7.074), lack of ANC visits (AOR = 6.828, 95% CI: 1.966-23.721), and absence of iron supplementation (AOR = 29.588, 95% CI: 2.922-299.713). Notably, a higher consumption of meat per week was associated with a reduced risk of anemia (AOR = 0.198, 95% CI: 0.104-0.379). CONCLUSION: The study underscores the severity of anemia in pregnant women within the range considered as severe public health problem by WHO. It is crucial to emphasize effective prenatal care, improve dietary practices, and promote the provision of iron supplements. Enhanced maternal education on Anemia during ANC visits has the potential to reduce Anemia prevalence and mitigate adverse maternal and neonatal outcomes.

Prophylactic common iliac artery temporary clamping versus balloon occlusion for management of placenta accreta spectrum disorders: A prospective clinical trial.

OBJECTIVE: The present study aims to compare prophylactic common iliac artery (CIA) temporary clamping and preoperative balloon occlusion for managing placenta accreta spectrum (PAS) disorders. STUDY DESIGN: Between January 2019 and June 2020, 46 patients with PAS disorders were included. Of them, 26 patients were offered CIA balloon occlusion (Group A), while temporary CIA clamping was done for the other 20 patients (Group B). Primary outcomes were procedure-related complications, and secondary outcomes included intraoperative and postoperative complications, reoperation rates, total procedure time, blood loss, and amount of blood transfusion. RESULTS: Blood loss was statistically non-significant higher in group B than in group A (p-value = 0.143). Only one patient in group A and three in group B needed reoperation. The bleeding continued for a mean of 1.6 days in group A and 1.7 days in group B, with non-significant statistical differences between both groups p value = 0.71. Nine patients in group A (34.6%) and four in group B (20%) required ICU admission. The mean Apgar score was 7 and 6.6 in babies of group A and group B patients, respectively. The median number of allogeneic blood transfusions performed was two in patients in group A and 1 in group B (p-value = 0.001). CONCLUSION: Both techniques offer good choices for patients with PAS to decrease mortality and morbidity rates. The selection of a better technique depends on institutional references and physicians' experience.

Statin Use and Incidence of Parkinson's Disease in Women from the French E3N Cohort Study.

BACKGROUND: Statins represent candidates for drug repurposing in Parkinson's disease (PD). Few studies examined the role of reverse causation, statin subgroups, and dose-response relations based on time-varying exposures. OBJECTIVES: We examined whether statin use is associated with PD incidence while attempting to overcome the limitations described previously, especially reverse causation. METHOD: We used data from the E3N cohort study of French women (follow-up, 2004-2018). Incident PD was ascertained using multiple sources and validated by experts. New statin users were identified through linked drug claims. We set up a nested case-control study to describe trajectories of statin prescriptions and medical consultations before diagnosis. We used time-varying multivariable Cox proportional hazards regression models to examine the statins-PD association. Exposure indexes included ever use, cumulative duration/dose, and mean daily dose and were lagged by 5 years to address reverse causation. RESULTS: The case-control study (693 cases, 13,784 controls) showed differences in case-control trajectories, with changes in the 5 years before diagnosis in cases. Of 73,925 women (aged 54-79 years), 524 developed PD and 11,552 started using statins in lagged analyses. Ever use of any statin was not associated with PD (hazard ratio [HR] = 0.87, 95% confidence interval [CI] = 0.67-1.11). Alternatively, ever use of lipophilic statins was significantly associated with lower PD incidence (HR = 0.70, 95% CI = 0.51-0.98), with a dose-response relation for the mean daily dose (P-linear trend = 0.02). There was no association for hydrophilic statins. CONCLUSION: Use of lipophilic statins at least 5 years earlier was associated with reduced PD incidence in women, with a dose-response relation for the mean daily dose. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Curcumin loaded liposome formulation: Enhanced efficacy on performance, flesh quality, immune response with defense against Streptococcus agalactiae in Nile tilapia (Orechromis niloticus).

Application of novel trend comprising antioxidant phytogenics is aiming to minimize the stress related factors and associated diseases in intensive fish culturing. Today, the concept of exploiting and protecting natural antioxidants represents a paradigm shift for the aqua feed industry. Therefore, our principal goal targeting liposome as a novel nanocarrier for curcumin is directed to attain superior performance, fillet antioxidant stability and bacterial resistance in Nile tilapia. A total of 500 Nile tilapia fingerlings (average body weight, 10.27 ± 0.10 g) assigned into five experimental groups in 25 glass aquaria of 120 L capacity at the density 20 fish/aquaria. The experimental groups were supplemented with varying doses of liposomal curcumin-NPs, LipoCur-NPs (0, 5, 15, 25 and 35 mg/kg diet) were reared for 12 weeks and later Streptococcus agalactiae (S. agalactiae) challenged model was performed. Inclusion of LipoCur-NPs (25 and 35 mg/kg diet) had the most prominent impact on Nile tilapia growth rate and feed conversion ratio. The immune boosting outcomes post supplementing 35 mg/kg diet of LipoCur-NPs were evidenced by higher myeloperoxidase, lysozyme and total immunoglobulin levels. Even after 4 weeks frozen storage, LipoCur-NPs at the dose of 35 mg/kg diet prominently increased (P < 0.05) the fillet scavenging capability for free radicals (1,1-diphenyl-2-picrylhydrazyl and 2,2'-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) with an inverse reduction in lipid peroxidation biomarker (malondialdehyde). Notably, upregulation of GSH-Px, CAT, and SOD genes in fillet of 35 mg/kg LipoCur-NPs fed fish coordinated with higher T-AOC and lower oxidative markers (ROS and H2O2). Post S. agalactiae challenge, higher supplementation levels of LipoCur-NPs (35 mg/kg diet) greatly attenuated the expression of its vital virulence genes (cfb, fbsA and cpsA) with higher expression of Igm, CXC-chemokine and MHC genes. Concordantly, downregulation of inflammatory markers (IL-1ß, TNF-α and IL-8) and upregulation of anti-inflammatory ones (IL-10 and TGF-ß) were remarkably documented. Based on these findings, the innovative curcumin loaded liposome was considered a novel multitargeting alternative not only playing an imperative role in Nile tilapia growth promotion and fillet stability upon storage, but also protecting efficiently against S. agalactiae.

Prevalence and factors associated with immunization coverage among children under five years in Mohamed Mooge health center, Hargeisa, Somaliland: a cross-sectional study.

BACKGROUND: Routine immunization contributes greatly to reduction in mortality from vaccine preventable diseases among children. The Somaliland Demographic and Health survey, 2020 revealed that only 13.7% of children in Marodijeh (Hargeisa) region had received all recommended vaccines, which is far below the World Health Organization (WHO) target of 80%. We therefore, assessed factors associated with immunization coverage among children under five years at Mohamed Mooge Health Center in Hargeisa, Somaliland. METHODS: Institutional based cross-sectional study was conducted on 174 systematically sampled, consented mothers that visited Mohamed Mooge Health Center for antenatal care during December 2022 to May 2023. Data was collected using a structured questionnaire. Data was analysed using SPSS and the relationship between dependent and independent variables was checked chi-square test at p ≤ 0.05. Finally, candidate variables were tested by using multivariate logistic regression in order to control potential confounders and the result was presented using AOR and 95% confidence interval. Model fitness was checked using Hosmer-Lemeshaw goodness of fit test with P > 0.05 for fitness. Multicollinearity between variables was checked using correlation coefficients at 0.80 or higher.  RESULT: Among 174 study participants, the prevalence of overall vaccine completion in this study was 55.3%. Women who had being aware about childhood immunization on BCG vaccination (AOR = 3.887; 95% CI: 1.275, 6.844), pentavalent (AOR = 11.385; 95% CI: 5.424-14.464), and measles (AOR = 3.074; 95% CI: 1.822-6.130) had higher odds of having immunized their children. Mothers who had employment had higher odds of having their children immunized against measles (AOR = 4.069; 95% CI: 1.822-6.130) compared to those who had not. CONCLUSIONS: Full immunization coverage was lower than the target set by the World Health Organization in this study area. The current study revealed that, the mother's awareness of childhood vaccinations on BCG, pentavalent, measles and employment status of mothers were positively associated with immunization coverage. To promote vaccination coverage, the government should implement a national awareness campaign on childhood immunization and increase the number of outreach services.

Correlation of Eustachian tube function with the results of type 1 tympanoplasty: a prospective study.

OBJECTIVES: This study aims to evaluate Eustachian tube (ET) function tests and their impact on outcomes of tympanoplasty in patients with inactive chronic suppurative otitis media. MATERIALS AND METHODS: A prospective study was conducted involving patients diagnosed with chronic suppurative otitis media (CSOM) and having a central dry perforation. Assessment of the ET function was done for all included cases by three tests; pressure swallow equalization test, saccharine test and methylene blue test. The primary outcome is the graft success rate defined as intact graft without any residual perforation at 6 months postoperatively. Secondary outcomes include hearing assessment and possible associated complications. RESULTS: 64 patients were included in the study with an average age of 36.59 ± 11.96 years. All patients underwent assessment of the ET function by saccharine test, methylene blue test and pressure equalization test (PET) followed by microscopic post-auricular tympanoplasty. Successful tympanoplasty is achieved in 93.75% of cases with residual perforation in four patients. Mean air-bone gap is significantly improved from 23.73 ± 2.80 preoperatively to 10.93 ± 5.46 postoperatively. Results of Methylene blue test has no statistical impact on graft take rate (p value = 0.379), while saccharine test and pressure equalization test results have statistically significant correlation with graft success (p value ≤ 0.001). CONCLUSIONS: Saccharine and Pressure equalization tests have a good positive correlation with the graft healing in tympanoplasty, while methylene blue test was found to have no correlation with the success rate.

Analysis of CyberKnife intracranial treatment plans using ICRU 91 dose reporting: A retrospective study.

ICRU 91, published in 2017, is an international standard for prescribing, recording, and reporting stereotactic treatments. Since its release, there has been limited research published on the implementation and impact of ICRU 91 on clinical practice. This work provides an assessment of the recommended ICRU 91 dose reporting metrics for their use in clinical treatment planning. A set of 180 intracranial stereotactic treatment plans for patients treated by the CyberKnife (CK) system were analyzed retrospectively using the ICRU 91 reporting metrics. The 180 plans comprised 60 trigeminal neuralgia (TGN), 60 meningioma (MEN), and 60 acoustic neuroma (AN) cases. The reporting metrics included the planning target volume (PTV) near-minimum dose ( D near - min ${D}_{{\rm{near}} - {\rm{min}}}$ ), near-maximum dose ( D near - max ${D}_{{\rm{near}} - {\rm{max}}}$ ), and median dose ( D 50 % ${D}_{50{\rm{\% }}}$ ), as well as the gradient index (GI) and conformity index (CI). The metrics were assessed for statistical correlation with several treatment plan parameters. In the TGN plan group, owing to the small targets, D near - min ${D}_{{\rm{near}} - {\rm{min}}}$ was greater than D near - max ${D}_{{\rm{near}} - {\rm{max}}}$ in 42 plans, whereas both metrics were not applicable in 17 plans. The D 50 % ${D}_{50{\rm{\% }}}$ metric was predominantly influenced by the prescription isodose line (PIDL). The GI was significantly dependent on target volume in all analyses performed, where the variables were inversely related. The CI was only dependent on target volume in treatment plans for small targets. The ICRU 91 D near - min ${D}_{{\rm{near}} - {\rm{min}}}$ and D near - max ${D}_{{\rm{near}} - {\rm{max}}}$ metrics breakdown in plans for small target volumes below 1 cm3 ; the Min and Max pixel should be reported in such cases. The D 50 % ${D}_{50{\rm{\% }}}$ metric is of limited use for treatment planning. Given their volume dependence, the GI and CI metrics could potentially serve as plan evaluation tools in the planning of the sites analyzed in this study, which would ultimately improve treatment plan quality.

An in vitro study measuring marginal gaps of inlay restorations fabricated from different CAD-CAM materials after thermocycling.

BACKGROUND: Many monolithic machined materials have been introduced and provided a suitable mechanical and physical properties for inlay restorations. However, there is shortage in the studies evaluating the marginal adaptation using these materials. PURPOSE: This study aimed to compare the effect of fabricating inlay restorations from 3 different CAD-CAM materials on marginal gaps before and after thermocycling. MATERIALS AND METHODS: Sixty human premolars were randomly divided into 3 groups (n = 20) according to the material used: (e.max CAD, Ivoclar AG, Schaan, Liechtenstein), (HC, Shofu, Koyoto, Japan) and (Brilliant Crios, Coltene, Altstätten, Switzerland) (n = 20). A scanning electron microscope (SEM) (JSM- 6510 lv, JEOL, Tokyo, JAPAN) was used to for measuring the marginal gaps after cementation of inlay restorations. The magnification was adapted to 250x. Marginal gaps were revaluated with SEM after thermocycling. The temperatures of baths were 5 and 55 °C was applied for a total of 5000 cycles. All data were statistically analyzed by using ANCOVA to demonstrate if there were any statistically significant differences between the gap measures after thermocycling of the three independent (unrelated) groups. A Bonferroni adjustmen was used to perform post hoc analysis (α = 0.05). RESULTS: Post-intervention marginal gap was statistically significantly lower in group EX (110.8 µm) which was statistically significant compared with group SF (112.5 µm) (mean difference=-1.768, P = .007) and group BR (113 µm) (mean difference=-2.272, P = .001), however, in. comparing SF and BR groups, there was no significant difference (mean difference=-0.5, P = .770). CONCLUSIONS: Thermocycling affected the marginal gaps of composite based restoration and resin-modified ceramics widely. However, it had a very small effect on glass ceramics marginal adaptation. CLINICAL IMPLICATIONS: The marginal gaps of CAD-CAM inlays varied according to material used (ceramic based, combination, or resin based). Thermocycling has a minor effect on the marginal adaptation of lithium disilicate glass-ceramic inlays, where it affected the margin of resin-modified ceramic and composite based inlays greatly. Using lithium disilicate glass-ceramic might improve the clinical longevity of inlay restored teeth.

Identifying Protective Drugs for Parkinson's Disease in Health-Care Databases Using Machine Learning.

BACKGROUND: Available treatments for Parkinson's disease (PD) are only partially or transiently effective. Identifying existing molecules that may present a therapeutic or preventive benefit for PD (drug repositioning) is thus of utmost interest. OBJECTIVE: We aimed at detecting potentially protective associations between marketed drugs and PD through a large-scale automated screening strategy. METHODS: We implemented a machine learning (ML) algorithm combining subsampling and lasso logistic regression in a case-control study nested in the French national health data system. Our study population comprised 40,760 incident PD patients identified by a validated algorithm during 2016 to 2018 and 176,395 controls of similar age, sex, and region of residence, all followed since 2006. Drug exposure was defined at the chemical subgroup level, then at the substance level of the Anatomical Therapeutic Chemical (ATC) classification considering the frequency of prescriptions over a 2-year period starting 10 years before the index date to limit reverse causation bias. Sensitivity analyses were conducted using a more specific definition of PD status. RESULTS: Six drug subgroups were detected by our algorithm among the 374 screened. Sulfonamide diuretics (ATC-C03CA), in particular furosemide (C03CA01), showed the most robust signal. Other signals included adrenergics in combination with anticholinergics (R03AL) and insulins and analogues (A10AD). CONCLUSIONS: We identified several signals that deserve to be confirmed in large studies with appropriate consideration of the potential for reverse causation. Our results illustrate the value of ML-based signal detection algorithms for identifying drugs inversely associated with PD risk in health-care databases. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Modular Single-Stage Three-Phase Flyback Differential Inverter for Medium/High-Power Grid Integrated Applications.

This paper proposes a single-stage three-phase modular flyback differential inverter (MFBDI) for medium/high power solar PV grid-integrated applications. The proposed inverter structure consists of parallel modules of flyback DC-DC converters based on the required power level. The MFBDI offers many features for renewable energy applications, such as reduced components, single-stage power processing, high-power density, voltage-boosting property, improved footprint, flexibility with modular extension capability, and galvanic isolation. The proposed inverter has been modelled, designed, and scaled up to the required application rating. A new mathematical model of the proposed MFBDI is presented and analyzed with a time-varying duty-cycle, wide-range of frequency variation, and power balancing in order to display its grid current harmonic orders for grid-tied applications. In addition, an LPF-based harmonic compensation strategy is used for second-order harmonic component (SOHC) compensation. With the help of the compensation technique, the grid current THD is reduced from 36% to 4.6% by diminishing the SOHC from 51% to 0.8%. Moreover, the SOHC compensation technique eliminates third-order harmonic components from the DC input current. In addition, a 15% parameters mismatch has been applied between the flyback parallel modules to confirm the modular operation of the proposed MFBDI under modules divergence. In addition, SiC MOSFETs are used for inverter switches implementation, which decrease the inverter switching losses at high-switching frequency. The proposed MFBDI is verified by using three flyback parallel modules/phase using PSIM/Simulink software, with a rating of 5 kW, 200 V, and 50 kHz switching frequency, as well as experimental environments.

Azides in the Synthesis of Various Heterocycles.

In this review, we focus on some interesting and recent examples of various applications of organic azides such as their intermolecular or intramolecular, under thermal, catalyzed, or noncatalyzed reaction conditions. The aforementioned reactions in the aim to prepare basic five-, six-, organometallic heterocyclic-membered systems and/or their fused analogs. This review article also provides a report on the developed methods describing the synthesis of various heterocycles from organic azides, especially those reported in recent papers (till 2020). At the outset, this review groups the synthetic methods of organic azides into different categories. Secondly, the review deals with the functionality of the azido group in chemical reactions. This is followed by a major section on the following: (1) the synthetic tools of various heterocycles from the corresponding organic azides by one-pot domino reaction; (2) the utility of the chosen catalysts in the chemoselectivity favoring C-H and C-N bonds; (3) one-pot procedures (i.e., Ugi four-component reaction); (4) nucleophilic addition, such as Aza-Michael addition; (5) cycloaddition reactions, such as [3+2] cycloaddition; (6) mixed addition/cyclization/oxygen; and (7) insertion reaction of C-H amination. The review also includes the synthetic procedures of fused heterocycles, such as quinazoline derivatives and organometal heterocycles (i.e., phosphorus-, boron- and aluminum-containing heterocycles). Due to many references that have dealt with the reactions of azides in heterocyclic synthesis (currently more than 32,000), we selected according to generality and timeliness. This is considered a recent review that focuses on selected interesting examples of various heterocycles from the mechanistic aspects of organic azides.

Curcumin and Its Derivatives Induce Apoptosis in Human Cancer Cells by Mobilizing and Redox Cycling Genomic Copper Ions.

Turmeric spice contains curcuminoids, which are polyphenolic compounds found in the Curcuma longa plant's rhizome. This class of molecules includes curcumin, demethoxycurcumin, and bisdemethoxycurcumin. Using prostate cancer cell lines PC3, LNCaP, DU145, and C42B, we show that curcuminoids inhibit cell proliferation (measured by MTT assay) and induce apoptosis-like cell death (measured by DNA/histone ELISA). A copper chelator (neocuproine) and reactive oxygen species scavengers (thiourea for hydroxyl radical, superoxide dismutase for superoxide anion, and catalase for hydrogen peroxide) significantly inhibit this reaction, thus demonstrating that intracellular copper reacts with curcuminoids in cancer cells to cause DNA damage via ROS generation. We further show that copper-supplemented media sensitize normal breast epithelial cells (MCF-10A) to curcumin-mediated growth inhibition, as determined by decreased cell proliferation. Copper supplementation results in increased expression of copper transporters CTR1 and ATP7A in MCF-10A cells, which is attenuated by the addition of curcumin in the medium. We propose that the copper-mediated, ROS-induced mechanism of selective cell death of cancer cells may in part explain the anticancer effects of curcuminoids.

Novel Pyridinium Based Ionic Liquid Promoter for Aqueous Knoevenagel Condensation: Green and Efficient Synthesis of New Derivatives with Their Anticancer Evaluation.

Herein, a distinctive dihydroxy ionic liquid ([Py-2OH]OAc) was straightforwardly assembled from the sonication of pyridine with 2-chloropropane-1,3-diol by employing sodium acetate as an ion exchanger. The efficiency of the ([Py-2OH]OAc as a promoter for the sono-synthesis of a novel library of condensed products through DABCO-catalyzed Knoevenagel condensation process of adequate active cyclic methylenes and ninhydrin was next investigated using ultimate greener conditions. All of the reactions studied went cleanly and smoothly, and the resulting Knoevenagel condensation compounds were recovered in high yields without detecting the aldol intermediates in the end products. Compared to traditional strategies, the suggested approach has numerous advantages including mild reaction conditions with no by-products, eco-friendly solvent, outstanding performance in many green metrics, and usability in gram-scale synthesis. The reusability of the ionic liquid was also studied, with an overall retrieved yield of around 97% for seven consecutive runs without any substantial reduction in the performance. The novel obtained compounds were further assessed for their in vitro antitumor potential toward three human tumor cell lines: Colo-205 (colon cancer), MCF-7 (breast cancer), and A549 (lung cancer) by employing the MTT assay, and the findings were evaluated with the reference Doxorubicin. The results demonstrated that the majority of the developed products had potent activities at very low doses. Compounds comprising rhodanine (5) or chromane (12) moieties exhibited the most promising cytotoxic effects toward three cell lines, particularly rhodanine carboxylic acid derivative (5c), showing superior cytotoxic effects against the investigated cell lines compared to the reference drug. Furthermore, automated docking simulation studies were also performed to support the results obtained.

High-Pressure Metal-Free Catalyzed One-Pot Two-Component Synthetic Approach for New 5-Arylazopyrazolo[3,4-b]Pyridine Derivatives.

An appropriate and efficient Q-tube-assisted ammonium acetate-mediated protocol for the assembly of the hitherto unreported 5-arylazopyrazolo[3,4-b]pyridines was demonstrated. This methodology comprises the cyclocondensation reaction of 5-amino-2-phenyl-4H-pyrazol-3-one with an assortment of arylhydrazonals in an NH4OAc/AcOH buffer solution operating a Q-tube reactor. This versatile protocol exhibited several outstanding merits: easy work-up, mild conditions, scalability, broad substrate scope, safety (the Q-tube kit is simply for pressing and sealing), and a high atom economy. Consequently, performing such reactions under elevated pressures and utilizing the Q-tube reactor seemed preferable for achieving the required products in comparison to the conventional conditions. Diverse spectroscopic methods and X-ray single-crystal techniques were applied to confirm the proposed structure of the targeted compounds.

Visualization of Platelet Integrins via Two-Photon Microscopy Using Anti-transmembrane Domain Peptides Containing a Blue Fluorescent Amino Acid.

The fluorescent reporters commonly used to visualize proteins can perturb both protein structure and function. Recently, we found that 4-cyanotryptophan (4CN-Trp), a blue fluorescent amino acid, is suitable for one-photon imaging applications. Here, we demonstrate its utility in two-photon fluorescence microscopy by using it to image integrins on cell surfaces. Specifically, we used solid-phase peptide synthesis to generate CHAMP peptides labeled with 4-cyanoindole (4CNI) at their N-termini to image integrins on cell surfaces. CHAMP (computed helical anti-membrane protein) peptides spontaneously insert into membrane bilayers to target integrin transmembrane domains and cause integrin activation. We found that 4CNI labeling did not perturb the ability of CHAMP peptides to insert into membranes, bind to integrins, or cause integrin activation. We then used two-photon fluorescence microscopy to image 4CNI-containing integrins on the surface of platelets. Compared to a 4CNI-labeled scrambled peptide that uniformly decorated cell surfaces, 4CNI-labeled CHAMP peptides were present in discrete blue foci. To confirm that these foci represented CN peptide-containing integrins, we co-stained platelets with integrin-specific fluorescent monoclonal antibodies and found that CN peptide and antibody fluorescence coincided. Because 4CNI can readily be biosynthetically incorporated into proteins with little if any effect on protein structure and function, it provides a facile way to directly monitor protein behavior and protein-protein interactions in cellular environments. In addition, these results clearly demonstrate that the two-photon excitation cross section of 4CN-Trp is sufficiently large to make it a useful two-photon fluorescence reporter for biological applications.

New adaptive lasso approaches for variable selection in automated pharmacovigilance signal detection.

BACKGROUND: Adverse effects of drugs are often identified after market introduction. Post-marketing pharmacovigilance aims to detect them as early as possible and relies on spontaneous reporting systems collecting suspicious cases. Signal detection tools have been developed to mine these large databases and counts of reports are analysed with disproportionality methods. To address disproportionality method biases, recent methods apply to individual observations taking into account all exposures for the same patient. In particular, the logistic lasso provides an efficient variable selection framework, yet the choice of the regularization parameter is a challenging issue and the lasso variable selection may give inconsistent results. METHODS: We propose a new signal detection methodology based on the adaptive lasso. We derived two new adaptive weights from (i) a lasso regression using the Bayesian Information Criterion (BIC), and (ii) the class-imbalanced subsampling lasso (CISL), an extension of stability selection. The BIC is used in the adaptive lasso stage for variable selection. We performed an extensive simulation study and an application to real data, where we compared our methods to the existing adaptive lasso, and recent detection approaches based on lasso regression or propensity scores in high dimension. For both studies, we evaluate the methods in terms of false discoveries and sensitivity. RESULTS: In the simulations and the application, both proposed adaptive weights show equivalent or better performances than the other competitors, with an advantage for the CISL-based adaptive weights. CISL and lasso regression using BIC are solid alternatives. CONCLUSION: Our proposed adaptive lasso is an appealing methodology for signal detection in pharmacovigilance. Although we cannot rely on test theory, our approaches show a low and stable False Discovery Rate in all simulation settings. All methods evaluated in this work are implemented in the adapt4pv R package.

Tuning the electronic transition energy of indole via substitution: application to identify tryptophan-based chromophores that absorb and emit visible light.

Fluorescent amino acids (FAAs) offer significant advantages over fluorescent proteins in applications where the fluorophore size needs to be limited or minimized. A long-sought goal in biological spectroscopy/microcopy is to develop visible FAAs by modifying the indole ring of tryptophan. Herein, we examine the absorption spectra of a library of 4-substituted indoles and find that the frequency of the absorption maximum correlates linearly with the global electrophilicity index of the substituent. This finding permits us to identify two promising candidates, 4-formyltryptophan (4CHO-Trp) and 4-nitrotryptophan (4NO2-Trp), both of which can be excited by visible light. Further fluorescence measurements indicate that while 4CHO-indole (and 4CHO-Trp) emits cyan fluorescence with a reasonably large quantum yield (ca. 0.22 in ethanol), 4NO2-indole is essentially non-fluorescent, suggesting that 4CHO-Trp (4NO2-Trp) could be useful as a fluorescence reporter (quencher). In addition, we present a simple method for synthesizing 4CHO-Trp.

Weighted Kaplan-Meier estimators motivating to estimate HIV-1 RNA reduction censored by a limit of detection.

Measuring the magnitude of reduction in HIV-1 RNA levels accurately is difficult because many patients have a censored reduction due to the limit of detection (LOD) of the virologic assay being employed. The use of censored methods has improved the analysis of such reductions compared with crude methods but implies independent censoring. For HIV-1 RNA reduction data, the value at which a patient's HIV-1 RNA reduction becomes censored is mainly determined by the patient's baseline HIV-1 RNA level. We suggest two possibilities based on modification of the redistribution to the right algorithm to handle the situation of dependence either from a single continuous marker, that is, the baseline HIV-1 RNA level, or from multiple markers. Two series of simulation, one in the HIV-1 RNA setting and one in the classical censoring setting, compared performance of the previous methods with our suggestions. Our proposed estimators show good performances when the dependent censoring is due to LOD. Overall, in the classical censoring setting, our suggestions perform as well as other methods including the Inverse Probability of Censoring Weighted and the Kaplan-Meier imputation with Bootstrap. We applied those estimators to estimate the HIV-1 RNA reduction at week 8 of 502 patients who received a raltegravir-containing regimen and to data from the Mayo Clinic trial in primary biliary cirrhosis.

Blue fluorescent amino acid for biological spectroscopy and microscopy.

Many fluorescent proteins are currently available for biological spectroscopy and imaging measurements, allowing a wide range of biochemical and biophysical processes and interactions to be studied at various length scales. However, in applications where a small fluorescence reporter is required or desirable, the choice of fluorophores is rather limited. As such, continued effort has been devoted to the development of amino acid-based fluorophores that do not require a specific environment and additional time to mature and have a large fluorescence quantum yield, long fluorescence lifetime, good photostability, and an emission spectrum in the visible region. Herein, we show that a tryptophan analog, 4-cyanotryptophan, which differs from tryptophan by only two atoms, is the smallest fluorescent amino acid that meets these requirements and has great potential to enable in vitro and in vivo spectroscopic and microscopic measurements of proteins.