Physiological instability is linked to mortality in primary central nervous system lymphoma: A case–control fMRI study

Primary central nervous system lymphoma (PCNSL) is an aggressive brain disease where lymphocytes invade along perivascular spaces of arteries and veins. The invasion markedly changes (peri)vascular structures but its effect on physiological brain pulsations has not been previously studied. Using physiological magnetic resonance encephalography (MREG_BOLD) scanning, this study aims to quantify the extent to which (peri)vascular PCNSL involvement alters the stability of physiological brain pulsations mediated by cerebral vasculature. Clinical implications and relevance were explored. In this study, 21 PCNSL patients (median 67y; 38% females) and 30 healthy age‐matched controls (median 63y; 73% females) were scanned for MREG_BOLD signal during 2018–2021. Motion effects were removed. Voxel‐by‐voxel Coefficient of Variation (CV) maps of MREG_BOLD signal was calculated to examine the stability of physiological brain pulsations. Group‐level differences in CV were examined using nonparametric covariate‐adjusted tests. Subject‐level CV alterations were examined against control population Z‐score maps wherein clusters of increased CV values were detected. Spatial distributions of clusters and findings from routine clinical neuroimaging were compared [contrast‐enhanced, diffusion‐weighted, fluid‐attenuated inversion recovery (FLAIR) data]. Whole‐brain mean CV was linked to short‐term mortality with 100% sensitivity and 100% specificity, as all deceased patients revealed higher values (n = 5, median 0.055) than surviving patients (n = 16, median 0.028) (p < .0001). After adjusting for medication, head motion, and age, patients revealed higher CV values (group median 0.035) than healthy controls (group median 0.024) around arterial territories (p ≤ .001). Abnormal clusters (median 1.10 × 10⁵mm³) extended spatially beyond FLAIR lesions (median 0.62 × 10⁵mm³) with differences in volumes (p = .0055).     

Oral ibuprofen in early curative closure of patent ductus arteriosus in very premature infants

Intravenous indomethacin and intravenous ibuprofen are widely used for the treatment of patent ductus arteriosus (PDA) in premature infants. Intravenous indomethacin may lead to renal impairment, enterocolitis, and intraventricular hemorrhage. Intravenous ibuprofen was shown to be as effective and to cause fewer side effects. If ibuprofen is effective intravenously, it will probably be effective orally, too. This study was conducted to test oral ibuprofen in early curative closure of PDA in very premature infants hoping for a better tolerance and the same efficacy as intravenous ibuprofen. Forty very premature infants (mean gestational age: 29.4 +/- 1 to 2 weeks [range: 26 to 31.5 weeks]; mean weight: 1237.2 +/- 198 g [range: 650-1770 g]) with PDA and respiratory distress were studied prospectively. They received, while between 48 and 96 hours old, oral ibuprofen at a dose of 10 mg/kg, followed, if needed, at 24-hour intervals by one or two additional doses of 5 mg/kg each. Color Doppler echography of the heart, brain, and abdomen were performed before treatment and after each dose administration. Ductal closure, early outcome (1 week after treatment), and late outcome were recorded. Thirty-eight patients (95%) achieved pharmacological closure. Two patients did not respond to the treatment: One required surgical ligation of the ductus, and the other patient received and well tolerated ductal shunting. Twenty-four patients were treated with one dose of oral ibuprofen, 10 were treated with two doses, and 6 were treated with three doses. Early outcome showed no case of renal impairment, no significant differences in serum creatinine levels, nine cases (22.5%) of intraventricular hemorrhage, three cases (7.5%) of necrotizing enterocolitis, and two cases (5%) of gastrointestinal bleeding. Late outcome showed 15 cases (37.5%) of nosocomial sepsis, 3 cases (7.5%) of chronic lung disease, 2 cases (5%) of periventricular leukomalacia, and 17 cases of death. In this study, oral ibuprofen was effective and well tolerated for early curative closure of PDA in very premature infants. Nevertheless, larger randomized comparative studies with pharmacokinetics measures are warranted.     

The IUGR prognostic scale

OBJECTIVE: Complex evaluation of the functional system "mother-placenta-fetus" in intrauterine growth restriction (IUGR) for the prognosis of risk of perinatal complications and optimization of choice of method of delivery. METHODS: We created an objective scale for the evaluation of pregnancies complicated by IUGR using 19 fetometric, dopplerometric and pulsometric parameters. We prospectively followed 130 fetuses classified into three risk groups determined by our prognostic scale with a control group of 25. Operative method of delivery was recommended for medium and high risk groups. We examined newborns with the help of neurosonography and compared them to 139 retrospective newborns classified into three groups according to severity of IUGR with a control group of 25. RESULTS: C-sections were higher by 27 and 12% in the prospective medium and high risk groups. Ventriculomegaly, brain edema, hemorrhages and pathological vascular pulsation decreased by 9, 27, 12 and 21%. Perinatal mortality decreased by 4%. CONCLUSIONS: The developed IUGR prognostic scale optimized the choice of method of delivery and led to decreased rates of neurological morbidity and mortality in newborns with IUGR.     

Hypersensitivity to aeroallergens in patients with recurrent vulvovaginitis of undetermined etiology

AIM: Recent findings show that the vaginal mucosa can develop an allergic response to environmental allergens and there is a strong association between atopy and some recurrent vulvovaginal infections. In this study, we investigated prospectively the rate of atopy in patients with recurrent vulvovaginitis of undetermined etiology (RVV). MATERIAL AND METHODS: After being investigated by a gynecologist, 35 patients with RVV who were considered as undetermined etiology formed the study group. The control group consisted of 150 healthy females. Study and control groups were investigated for atopy by means of skin prick test for common aeroallergens. Associated allergic disease and familial atopy history of the subjects were recorded. RESULTS: The rate of atopy (11/35; 31.4% vs 9/150; 6%) was significantly higher (P < 0.001) in the study group than in the controls. Familial history of atopy was significantly more frequent in the study group than in the controls (10/35; 28.6% vs 8/150; 5.3%, P < 0.05). RVV in atopics is more associated with seasonal rhinitis than in nonatopics (5/11; 45.4% vs 2/24; 8.3%, P < 0.05). CONCLUSION: We concluded that a significant number of RVV is associated with atopy. Although the exact mechanism(s) of this relationship remains to be investigated atopy might be a causative and/or contributing factor in the pathogenesis of RVV.     

Microstructural Evolution,Tensile Failure,Fatigue Behavior and Wear Properties of Al2O3 Reinforced Al2014 Alloy T6 Heat Treated Metal Composites

The paper focused on an experimental study on the microstructural, mechanical, and wear characteristics of 15 wt.% alumina (Al₂O₃) particulates with an average particle size of 20 µm, reinforced in Al2014 alloy matrix composite as-cast and heat-treated samples. The metal matrix composite (MMC)samples were produced via a novel two-stage stir-casting technique. The fabricated composite samples were subjected to evaluate hardness, tensile strength, fatigue behavior and wear properties for both as cast and T6 heat-treated test samples. The Al2014 alloy and Al2014-15 wt.% Al₂O₃ MMCs were in solution for 1 h at a temperature of 525 °C, quenched instantly in cold water, and then artificially aged for 10 h at a temperature of 175 °C. SEM and X-ray diffraction analyses were used to investigate the microstructure and dispersion of the reinforced Al₂O₃ particles in the composite and the base alloy Al2014. The obtained results indicated that the hardness, tensile and fatigue strength and wear resistance increased when an amount of Al₂O₃ particles was added, compared to the as-cast Al2014 alloy and it was observed that after subjecting the same composite samples to heat treatment, there was further enhancement in the mechanical and wear properties in the Al2014 matrix alloy and Al2014-15 wt.% Al₂O₃ composite samples.     

Prevalence and correlates of COVID-19 vaccine hesitancy among the elderly in Qatar: A cross-sectional study

Older individuals are more vulnerable to severe coronavirus disease 2019 and medical complications. Vaccination stands as an efficient and safe vanguard against infection. However, negative attitudes and perceptions pertaining to available vaccines might hinder community inoculation. The aim of this study was to assess vaccine hesitancy and its psychosocial determinants among the elderly in Qatar.We conducted a cross-sectional study between October 15 and November 15, 2020, using a composite online survey including the Vaccine Attitudes Examination Scale in addition to questions on sociodemographic correlates and the role of healthcare professionals.The vaccine hesitancy rate was 19.5%. The main reasons for willingness to vaccinate included understanding the nature of disease and role of vaccination, in addition to information provided by physicians. Fears mainly centered around vaccine safety. Vaccine hesitators were more likely to be non-Qatari and having received the influenza vaccine at least once. Gender, marital status, socioeconomic status, educational level, and having completed childhood vaccinations were not associated with vaccine hesitancy.Efforts should be directed toward raising awareness of vaccine efficacy and safety profiles. Physicians should additionally be educated about their pivotal role in advocating vaccine acceptance. We recommend reassessing vaccine hesitancy and its associated factors following a year of campaigning and vaccine administration to identify and target vulnerable groups.     

A novel construct of an electrochemical acetylcholinesterase biosensor for the investigation of malathion sensitivity to three different insect species using a NiCr2O4/g-C3N4 composite integrated pencil graphite electrode

Herein, an electrochemical biosensor has been prepared to assess the sensitivity of an organophosphate insecticide, malathion, to acetylcholinesterase (AChE) enzyme of three insects including Apis mellifera (honeybee), Tribolium castaneum (red flour beetle), and Zootermopsis nevadensis (dampwood termite). A composite of nickel chromite (NiCr₂O₄) and graphitic carbon nitride (g-C₃N₄) was prepared and characterized for its morphological, chemical and electrical properties. The NiCr₂O₄/g-C₃N₄ composite integrated pencil graphite electrodes were used to covalently immobilize insect AChE enzymes and amperometric response of bioelectrodes was determined through cyclic voltammetry. The prepared bioelectrodes exhibited high enzyme immobilization efficiency and electro-catalytic performance. The integrated bioelectrodes could efficiently detect malathion induced inhibition of insects'' AChEs. The linear ranges for malathion were found to be 0.1–1.6 μM, 1–40 nM and 2–100 nM, and LODs were 2 nM, 0.86 nM and 2.3 nM for A. mellifera, T. castaneum, and Z. nevadensis, respectively. Additionally, the biosensing platform developed using A. mellifera AChE was found highly sensitive and effective for malathion recoveries from spiked wheat flour samples with high recovery rates. Moreover, the proposed method was adequately reproducible and selective. The results revealed that A. mellifera AChE is less sensitive to inhibition by malathion as compared to T. castaneum, and Z. nevadensis AChE. The experimental results were validated through computational docking of malathion with insect AChEs and the results were in correspondence to experimental outcomes. The proposed method can be a plausible alternate to conventional analytical methods to assess the pesticide sensitivity and toxicity of various compounds against insect enzymes.

An innovative electrochemical assay has been established to determine pesticide sensitivity against acetylcholinesterase and possible toxicity against insects. The analytical efficiency of three common insect AChEs was determined through this method.     

Prediction of Compressive Strength of Sustainable Foam Concrete Using Individual and Ensemble Machine Learning Approaches

The entraining and distribution of air voids in the concrete matrix is a complex process that makes the mechanical properties of lightweight foamed concrete (LFC) highly unpredictable. To study the complex nature of aerated concrete, a reliable and robust prediction model is required, employing different machine learning (ML) techniques. This study aims to predict the compressive strength of LFC by using a support vector machine (SVM) as an individual learner along with bagging, boosting, and random forest (RF) as a modified ensemble learner. For that purpose, a database of 191 data points was collected from published literature, where the mix design ingredients, i.e., cement content, sand content, water to cement ratio, and foam volume, were chosen to predict the compressive strength of LFC. The 10-K fold cross-validation method and different statistical error and regression tools, i.e., mean absolute error (MAE), root means square error (RMSE), and coefficient of determinant (R²), were used to evaluate the performance of the developed ML models. The modified ensemble learner (RF) outperforms all models by yielding a strong correlation of R² = 0.96 along with the lowest statistical error values of MAE = 1.84 MPa and RMSE = 2.52 MPa. Overall, the result suggests that the ensemble learners would significantly enhance the performance and robustness of ML models.     

Effect of Surface Tooling Techniques of Medical Titanium Implants on Bacterial Biofilm Formation In Vitro

The aim of this study was to assess the biofilm formation of Streptococcus mutans, Staphylococcus aureus, Enterococcus faecalis, and Escherichia coli on titanium implants with CAD-CAM tooling techniques. Twenty specimens of titanium were studied: Titanium grade 2 tooled with a Planmeca CAD-CAM milling device (TiGrade 2), Ti₆Al₄V grade 5 as it comes from CAD-DMLS device (computer aided design-direct metal laser sintering device) (TiGrade 5), Ti₆Al₄V grade 23 as it comes from a CAD-CAM milling device (TiGrade 23), and CAD-DMLS TiGrade 5 polished with an abrasive disc (TiGrade 5 polished). Bacterial adhesion on the implants was completed with and without saliva treatment to mimic both extraoral and intraoral surgical methods of implant placement. Five specimens/implant types were used in the bacterial adhesion experiments. Autoclaved implant specimens were placed in petri plates and immersed in saliva solution for 30 min at room temperature and then washed 3× with 1× PBS. Bacterial suspensions of each strain were made and added to the specimens after saliva treatment. Biofilm was allowed to form for 24 h at 37 °C and the adhered bacteria was calculated. Tooling techniques had an insignificant effect on the bacterial adhesion by all the bacterial strains studied. However, there was a significant difference in biofilm formation between the saliva-treated and non-saliva-treated implants. Saliva contamination enhanced S. mutans, S. aureus, and E. faecalis adhesion in all material types studied. S. aureus was found to be the most adherent strain in the saliva-treated group, whereas E. coli was the most adherent strain in the non-saliva-treated group. In conclusion, CAD-CAM tooling techniques have little effect on bacterial adhesion. Saliva coating enhances the biofilm formation; therefore, saliva contamination of the implant must be minimized during implant placement. Further extensive studies are needed to evaluate the effects of surface treatments of the titanium implant on soft tissue response and to prevent the factors causing implant infection and failure.