Cellulases are enzymes that are attracting worldwide attention because of their ability to degrade cellulose in the lignocellulosic biomass and transform it into highly demanded bioethanol. The ...enzymatic hydrolysis of cellulose by cellulases into fermentable sugars is a crucial step in biofuel production, given the complex structure of lignocellulose. Due to cellulases’ unique ability to hydrolyze the very recaltricant nature of lignocellulosic biomass, the cellulase market demand is rapidly growing. Although cellulases have been used in industrial applications for decades, constant effort is being made in the field of enzyme innovation to develop cellulase mixtures/cocktails with improved performance. Given that the main producers of cellulases are of microbial origin, there is a constant need to isolate new microorganisms as potential producers of enzymes important for biofuel production. This review provides insight into current research on improving microbial cellulase production as well as the outlook for the cellulase market with commercial cellulase preparation involved in industrial bioethanol production.
Tularemia was diagnosed for a 33-year-old pregnant woman in Serbia after a swollen neck lymph node was detected at gestation week 18. Gentamicin was administered parenterally (120 mg/d for 7 d); the ...pregnancy continued with no complications and a healthy newborn was delivered. Treatment of tularemia optimizes maternal and infant outcomes.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, ODKLJ, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The aim of this study was to assess the association between cigarette smoking and health-related quality of life (HRQoL) among students in two different universities, and the potential mediating ...effect of depression. Participants were students who came for mandatory check-ups at Student Health Care Centers in two Universities in Serbia, differing by socio-politically and economically environments. Students completed socio-demographic questionnaire, Beck Depression Inventory (BDI) and the SF-36 questionnaire for assessment of HRQoL. In both populations, after adjustment for socio-demographic, behavioral and health factors, smoking was associated with poorer Mental Composite Score (MCS) and Physical Composite Score (PCS) (Belgrade 1,624 students: MCS β = 3.38, 95% confidence interval CI 1.31, 5.44, PCS β = 1.01, 95% CI -0.50, 2.52; Kosovska Mitrovica 514 students: MCS β = 5.06, 95% CI 1.74, 8.37, PCS β = 3.29, 95% CI 0.75, 5.83). After additional adjustment for BDI score, the observed associations were lost (Belgrade: MCS β = 1.12, 95% CI -0.57, 2.80, PCS β = -0.40, 95% CI -1.71, 0.92; Kosovska Mitrovica: MCS β = 0.77, 95% CI -2.06, 3.60, PCS β = 0.56, 95% CI -1.75, 2.87). Higher BDI score was associated with poorer PCS and MCS across all quintiles. The association of smoking with impairment of HRQoL among university students in two different settings was mediated by higher levels of depressive symptoms. These findings highlight the need for further research on the interaction between smoking, mental health and quality of life, with implications for prevention, diagnosis and treatment.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Valorization of unexploited crop waste for obtaining of potent bio-compounds.•Development of fast microwave-assisted extraction of artichoke leaves antioxidants.•Performing of detailed two-level ...optimization of the process parameters.•Achievement of higher yields of stronger antioxidants than in competitive reports.•Obtaining of maximal yields of antioxidants in less than minute.
This study has developed an improved and fast microwave-assisted procedure for extraction of high yields of natural antioxidants from artichoke leaves dust. The material is derived as an abundant residue remained after processing for the industrial tea blends preparation, having no commercial value.
A key factors for optimization of the total polyphenolic (TPC) and flavonoid content (TFC) and antioxidant activities have been determined by using single factor experiments along with a response surface methodology. The optimal conditions for maximizing the combination of TPC/TFC and antioxidant activity were obtained as follows: ethanol concentration 67.81%, extraction time 50 s, liquid/solid ratio 41.78 mL/g, microwave power 180 W, whereas the corresponding responses resulted in: TPC − 205.59 ± 7.30 mg GAE/g dw, TFC − 79.75 ± 1.12 mg QE/g dw, and FRAP −1008.14 ± 37.15 mmolFe2+/g dw. Only 14.7 µg/mL of the extract concentration is required to inhibit 50% of DPPH free radicals.
A comparative study confirmed that the proposed procedure yielded higher TPC, TFC and antioxidant activities than available extraction methods. It highlights a several fold reduced extraction time, caring an eco-friendly principle for obtaining of antioxidants from industrial, medicinal crop residues, which would be further easily valorized in food and pharmaceutical industry.
The acquired hemophilia A (AHA) is a life-threatening condition. The incidence of AHA is extremely low, which requires a multidisciplinary approach to diagnosis and treatment. This is case report of ...73-year-old man who presented with AHA secondary to severe acute respiratory syndrome Coronavirus 2 (SARS-CoV-2) pneumonia. The patient had extensive skin bleeding and hematomas. In the coagulation screening tests activated partial thromboplastin time (APTT) was prolonged with normal prothrombin time (PT), which was indication for further investigation. The APTT in a mixing study with normal plasma did not correct so clotting factors inhibitors were suspected. With signs of bleeding, extremely low factor VIII (FVIII) activity (2%) and presence of FVIII inhibitors, AHA was diagnosed and treatment initiated. Patient was treated with factor eight inhibitor bypassing agent (FEIBA) for three days, followed by long-term corticosteroid and cyclophosphamide therapy. Malignant and autoimmune diseases as the most common causes of AHA were ruled out. The patient had a good response to therapy with gradual normalization of APTT and FVIII activity. To the best of our knowledge, the present case is the first reported case of
AHA after SARS-CoV-2 pneumonia. The diagnosis of AHA should be suspected in a patient with bleeding into the skin and mucous membranes without a previous personal and family history of bleeding, and with isolated prolonged APTT. It is important to investigate any isolated prolongation of APTT in cooperation with clinical laboratory experts.
With the emergence of nano-enabled medical devices (MDs) for the use in human medicine, ensuring their safety becomes of crucial importance. Hemocompatibility is one of the major criteria for ...approval of all MDs in contact with blood (e.g. vascular grafts, stents, or valves). Silver nanoparticles (AgNPs) are among the most used nanomaterials for MDs due to their biocidal activity; however, detailed knowledge on their hemostatic effects is still lacking.
This study aimed to evaluate comprehensively AgNPs effects on hemostasis in human blood by exploiting combination of affordable and clinically relevant techniques.
Differently stabilized AgNPs were prepared using sodium bis(2-ethylhexyl)sulphosuccinate (AOT), polyvinylpyrrolidone (PVP), poly-L-lysine (PLL), and bovine serum albumin (BSA) as coating agents. They were tested for hemolytic activity, induction of platelet aggregation, plasmatic coagulation, thrombin generation, and hemostasis in whole blood.
All AgNPs were found to cause dose-dependent hemolysis. The BSA-, AOT-, and PVP-coated AgNPs delayed plasmatic coagulation, while only PLL-AgNPs inhibited plasmatic coagulation, induced platelet activation, and interfered with hemostasis by delaying clotting time and decreasing clot firmness in whole blood.
Obtained results demonstrate that a combination of different techniques should be used for reliable assessment of AgNPs hemostatic effects highlighting the need for a standardized approach in sampling and experimental protocols.
Celotno besedilo
Dostopno za:
DOBA, IJS, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Objective: the aim of the study was to examine the mediating role of stress in associations between online risky behavior and three factors, namely, real-life risky behaviors and information security ...awareness as risk factors, and life satisfaction as a protective factor. Method: participants were university students (N=883, 40.5% male, and 59.5% female) with an average age of M=21.93 years (SD=4.29). They filled out the Users’ Information Security Awareness Questionnaire, Youth self-reported delinquency and risk behaviors questionnaire, Life satisfaction scale and Perceived Stress Scale. Result: Mediational analysis revealed a mediating role of stress: stress had a partially mediating role in the association between real-life risky behaviors and online risky behavior, making the association stronger. However, stress had a fully mediating role in the association between life satisfaction and online risky behavior, that is, the association was non-significant in the presence of stress. Conclusions: Overall results indicate that stress experienced in real-life situations can be a trigger for online risky behavior in adolescents. Under stressed conditions, adolescents choose to focus on negative outcomes more frequently because they refocus their cognitive resources on emotion regulation and leave inhibitory processes necessary to prevent risky behaviors uncontrolled.
Severe acute respiratory infections (SARI) are estimated to be the cause of death in about 19% of all children younger than 5 years globally. The outbreak of coronaviral disease (COVID-19) caused by ...SARS-CoV-2, increased considerably the burden of SARI worldwide. We used data from a vaccine effectiveness study to identify the factors associated with SARS CoV-2 infection among hospitalized SARI patients. We recruited SARI patients at 3 hospitals in Serbia from 7 April 2022-1 May 2023. We collected demographic and clinical data from patients using a structured questionnaire, and all SARI patients were tested for SARS-CoV-2 by RT-PCR. We conducted an unmatched test negative case-control study. SARS-CoV-2 infected SARI patients were considered cases, while SARS CoV-2 negative SARI patients were controls. We conducted bivariate and multivariable logistic regression analysis in order to identify variables associated with SARS-CoV-2 infection. We included 110 SARI patients: 74 were cases and 36 controls. We identified 5 factors associated with SARS-CoV-2 positivity, age (OR = 1.04; 95% CI = 1.01-1.07), having received primary COVID-19 vaccine series (OR = 0.28; 95% CI = 0.09-0.88), current smoking (OR = 8.64; 95% CI = 2.43-30.72), previous SARS CoV-2 infection (OR = 3.48; 95% CI = 1.50-8.11) and number of days before seeking medical help (OR = 0.81; 95% CI = 0.64-1.02). In Serbia during a period of Omicron circulation, we found that older age, unvaccinated, hospitalized SARI patients, previously infected with SARS CoV-2 virus and those who smoked, were more likely to be SARS-CoV-2-positive; these patient populations should be prioritized for COVID vaccination.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Despite increasing use of silver nanoparticles (AgNPs) in different medicinal products, knowledge about their effects on hemostasis and platelets functionality is still scarce. Published scientific ...reports provide neither data on oxidative stress response of platelets to AgNPs nor information about the effects of AgNPs physicochemical properties on functionality and activation of platelets. This study aimed to explore the role of AgNPs surface functionalization on cell viability, particle uptake, oxidative stress response, and activation of platelets. Small sized, spherical AgNPs were surface functionalized by negatively charged sodium bis(2-ethylhexyl) sulphosuccinate (AOT), neutral polymer polyvinylpyrrolidone (PVP), positively charged polymer poly-l-lysine (PLL) and bovine serum albumin (BSA). Platelet viability, activation and particle uptake were evaluated by flow cytometry. Oxidative stress response was evaluated by measuring the levels of intracellular glutathione (GSH), peroxy and superoxide radicals using assays based on fluorescence dies. Cytotoxicity and uptake of AgNPs to platelets were found to be dose-dependent in a following order PLL-AgNP >> > BSA-AgNP > AOT-AgNP > PVP-AgNP. Particle internalization was further confirmed by transmission electron microscopy. Treatment of platelets with AgNPs induced superoxide radical formation, depletion of GSH and hyperpolarization of the mitochondrial membrane. Small, but statistically significant increase of P-selectin expression in cells treated with all AgNPs compared to non-treated controls evidenced AgNPs-induced activation of platelets. Increased PAC-1 expression was found only in platelets treated with PLL-AgNPs. Obtained results demonstrate that different surface decoration of AgNPs determines their biological effects on platelets highlighting the importance of careful design of AgNPs-based medicinal products regarding their biocompatibility and functionality.
Synopsis: Surface functionalization of silver nanoparticles (AgNPs) determines their interaction with platelets affecting cell viability, particle uptake, oxidative stress response, and platelets activation. Display omitted
•Response of platelets to silver nanoparticles (AgNPs) was evaluated.•Surface functionalization of AgNPs determines their effects on platelets.•Cytotoxicity and uptake of AgNPs in platelets is dose-dependent.•Mild activation of platelets by AgNPs was observed by P-selectin expression.•PAC-1 expression was found only for platelets treated by positively charged AgNPs.
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