No massive black holes in the Milky Way halo.

The gravitational wave detectors have unveiled a population of massive black holes that do not resemble those observed in the Milky Way1-3 and whose origin is debated4-6. According to one possible explanation, these black holes may have formed from density fluctuations in the early Universe (primordial black holes)7-9, and they should comprise from several to 100% of dark matter to explain the observed black hole merger rates10-12. If such black holes existed in the Milky Way dark matter halo, they would cause long-timescale gravitational microlensing events lasting years13. The previous experiments were not sufficiently sensitive to such events14-17. Here we present the results of the search for long-timescale microlensing events among the light curves of nearly 80 million stars located in the Large Magellanic Cloud that were monitored for 20 years by the OGLE survey18. We did not find any events with timescales longer than one year, whereas all shorter events detected may be explained by known stellar populations. We find that compact objects in the mass range from 1.8 × 10-4 to 6.3 M⊙ cannot compose more than 1% of dark matter, and those in the mass range from 1.3 × 10-5 to 860 M⊙ cannot make up more than 10% of dark matter. Thus, primordial black holes in this mass range cannot simultaneously explain a significant fraction of dark matter and gravitational wave events.

Risk factors for bariatric surgery in patients over 65 years of age-a multicenter retrospective cohort study.

PURPOSE: Societies are aging, life expectancy is increasing, and as a result, the percentage of elderly people in the population is constantly increasing. When qualifying patients over 65 years of age for bariatric surgery, the benefits and risks should be carefully assessed. Weighing risk factors against each other to improve the quality of life and better control of obesity-related diseases. The study aimed to determine risk factors for bariatric surgery among patients over 65 years of age. METHODS: A multicenter, retrospective analysis of patients undergoing laparoscopic bariatric procedures from 2008 to 2022. The patients were divided into two groups: complicated (C) and uncomplicated (UC). Uni- and multivariate logistic regression analysis was performed to obtain significant, independent risk factors. RESULTS: There were 20 (7.0%) patients in C group and 264 (93.0%) patients in UC group. The most common complication was intraperitoneal bleeding (8, 2.8). There was no postoperative mortality. The mean follow-up was 47.5 months. In a multivariate logistic regression analysis, length of stay and %EWL significantly corresponded to general complications (OR 1.173, OR 1.020). A higher weight loss before surgery lowered the risk for hemorrhagic events after surgery (OR 0.889). A longer length of stay corresponded to leak after surgery (OR 1.175). CONCLUSIONS: Bariatric and metabolic surgery appears to be a safe method of obesity treatment in patients over 65 years of age. The most common complication was intraperitoneal bleeding. A prolonged hospital stay may increase the risk of leakage, while a higher weight loss before the surgery may lower the risk of bleeding.

The outcomes of Re-Redo bariatric surgery-results from multicenter Polish Revision Obesity Surgery Study (PROSS).

The increasing prevalence of bariatric surgery has resulted in a rise in the number of redo procedures as well. While redo bariatric surgery has demonstrated its effectiveness, there is still a subset of patients who may not derive any benefits from it. This poses a significant challenge for bariatric surgeons, especially when there is a lack of clear guidelines. The primary objective of this study is to evaluate the outcomes of patients who underwent Re-Redo bariatric surgery. We conducted a retrospective cohort study on a group of 799 patients who underwent redo bariatric surgery between 2010 and 2020. Among these patients, 20 individuals underwent a second elective redo bariatric surgery (Re-Redo) because of weight regain (15 patients) or insufficient weight loss, i.e. < 50% EWL (5 patients). Mean BMI before Re-Redo surgery was 38.8 ± 4.9 kg/m2. Mean age was 44.4 ± 11.5 years old. The mean %TWL before and after Re-Redo was 17.4 ± 12.4% and %EBMIL was 51.6 ± 35.9%. 13/20 patients (65%) achieved > 50% EWL. The mean final %TWL was 34.2 ± 11.1% and final %EBMIL was 72.1 ± 20.8%. The mean BMI after treatment was 31.9 ± 5.3 kg/m2. Complications occurred in 3 of 20 patients (15%), with no reported mortality or need for another surgical intervention. The mean follow-up after Re-Redo was 35.3 months. Although Re-Redo bariatric surgery is an effective treatment for obesity, it carries a significant risk of complications.

Biochemical evidence for conformational variants in the anti-viral and pro-metastatic protein IFITM1.

Interferon induced transmembrane proteins (IFITMs) play a dual role in the restriction of RNA viruses and in cancer progression, yet the mechanism of their action remains unknown. Currently, there is no data about the basic biochemical features or biophysical properties of the IFITM1 protein. In this work, we report on description and biochemical characterization of three conformational variants/oligomeric species of recombinant IFITM1 protein derived from an Escherichia coli expression system. The protein was extracted from the membrane fraction, affinity purified, and separated by size exclusion chromatography where two distinct oligomeric species were observed in addition to the expected monomer. These species remained stable upon re-chromatography and were designated as "dimer" and "oligomer" according to their estimated molecular weight. The dimer was found to be less stable compared to the oligomer using circular dichroism thermal denaturation and incubation with a reducing agent. A two-site ELISA and HDX mass spectrometry suggested the existence of structural motif within the N-terminal part of IFITM1 which might be significant in oligomer formation. Together, these data show the unusual propensity of recombinant IFITM1 to naturally assemble into very stable oligomeric species whose study might shed light on IFITM1 anti-viral and pro-oncogenic functions in cells.

Human lung vascular endothelium may limit infection with HRV16 via IFN-ß-dependent mechanisms.

Human rhinovirus 16 (HRV16) may induce inflammatory and antiviral responses in the human lung vascular endothelium (ECs) and impair its barrier functions after infection. However, ECs may regain barrier and metabolic functions. Mechanisms of limitation of HRV16 infection in the lung vascular endothelium are unknown. Human lung vascular endothelium (HMVEC-L) was infected with HRV16. IFN-ß, OAS-1, and PKR expression was assessed by real-time PCR, flow cytometry, and confocal microscope. To prove the significance of IFN-ß in the limitation of HRV16 replication, HMVEC-Ls were preincubated with anti-IFN-ß Abs. To prove the involvement of OAS-1 and PKR in the IFN-dependent limitation of HRV16 replication, HMVEC-Ls were transfected with respective siRNA. HRV16 stimulated IFN-ß production and activated intracellular mechanisms of antiviral immunity based on OAS-1 and PKR activation. Blocking of IFN-ß contributed to the inhibition of intracellular mechanisms of antiviral immunity (OAS-1, PKR) and boosted replication of HRV16. Effective OAS-1 silencing by siRNA caused the increase of HRV16 copy numbers after HRV16 infection. siRNA upregulated the other genes related to the antiviral response. The infected lung vascular endothelium may limit the HRV16 infection. This limitation may be associated with the induction of IFN-ß-dependent intracellular mechanisms based on OAS-1 and PKR activity.

Effect of Primary Versus Revisional One Anastomosis Gastric Bypass (OAGB) on Fatty Acid Profile.

INTRODUCTION: One anastomosis gastric bypass (OAGB) is one option of a revisional procedure for failed sleeve gastrectomy. Moreover, it can be used as a primary bariatric procedure, and is an effective surgery resulting in significant weight loss and the resolution or improvement of obesity-associated medical problems, accompanied by low perioperative complications. However, as with any therapy, OAGB has its limitations, including micronutrient deficiency or malnutrition. In our study, we compared the fatty acid (FA) profile in serum of patients after both primary OAGB (pOAGB) and revisional OAGB (rOAGB) to identify potential postsurgical FA alterations. METHODS: This is a retrospective study on patients with obesity who underwent OAGB procedures (pOAGB n=68; rOAGB n=17), conducted from 2016 to 2018. In blood, we analyzed a series of biochemical parameters, and in the serum, the FA profile was determined using gas chromatography-mass spectrometry. RESULTS: The percentage of excess BMI loss (% EBMIL) after pOAGB was 73.5 ± 2.47% in comparison to 45.9 ± 4.15% in the rOAGB group (p<0.001). In contrast to the lack of effect of rOAGB on most polyunsaturated FAs, in the pOAGB group, there was a decrease in eicosapentaenoic acid, and eicosatetraenoic and docosahexaenoic acid levels (p<0.001). We also found a decrease in very long-chain FAs (VLCFAs) and an increase in branched-chain FAs (BCFAs) after both types of OAGB procedure. CONCLUSIONS: Both OAGB procedures improved the profile of most FAs, leading to a decrease in VLCFAs, which are considered harmful, and an improvement in BCFAs, which are considered to be beneficial. There is a need to further investigate the possibility of n-3 polyunsaturated FA supplementation after pOAGB, due to the large decrease in these FAs after pOAGB.

Systemic Immune Inflammation Index as a Key Predictor of Dialysis in Pediatric Chronic Kidney Disease with the Use of Random Forest Classifier.

BACKGROUND: Low-grade inflammation is a significant component of chronic kidney disease (CKD). Systemic immune inflammation index (SII), a newly defined ratio combining neutrophil, lymphocyte, and platelet counts, has not yet been evaluated in the pediatric CKD population nor in the context of CKD progression or dialysis. Thus, this study aimed to analyze the complete blood cell count (CBC)-driven parameters, including SII, in children with CKD and to assess their potential usefulness in the prediction of the need for chronic dialysis. METHODS: A single-center, retrospective study was conducted on 27 predialysis children with CKD stages 4-5 and 39 children on chronic dialysis. The data were analyzed with the artificial intelligence tools. RESULTS: The Random Forest Classifier (RFC) model with the input variables of neutrophil count, mean platelet volume (MPV), and SII turned out to be the best predictor of the progression of pediatric CKD into end-stage kidney disease (ESKD) requiring dialysis. Out of these variables, SII showed the largest share in the prediction of the need for renal replacement therapy. CONCLUSIONS: Chronic inflammation plays a pivotal role in the progression of CKD into ESKD. Among CBC-driven ratios, SII seems to be the most useful predictor of the need for chronic dialysis in CKD children.

The Influence of Selected Laser Engraving Parameters on Surface Conditions of Hybrid Metal Matrix Composites.

Hybrid metal matrix composites (HMMCs) are a special type of material, possessing combined properties that belong to alloys and metals according to market demands. Therefore, they are used in different areas of industry and the properties of this type of material are useful in engineering applications, e.g., in aircraft engines and electrotechnical parts. The structure of the material requires a number of scientific studies to develop an appropriate processing technology. The paper presents the susceptibility of material from the HMMCs group with the EN AC-44300 (AISi12(Fe)) aluminum alloy matrix with a two-component reinforcement made of alumina particles (AP) and aluminosilicate fibers (AF) to thermal treatment with a laser beam. During this process, laser engraving of the researched material with variable beam power Pav and variable speed of the laser head vl were carried out. A metallographic analysis of the material was carried out. After laser engraving, surface structural changes of the material were determined. The properties of the surface geometric structure of processed material were also examined. Presented studies concern laser engraving on the surface of composite from the HMMC group, which was made by vacuum infiltration. Thanks to this method, it is possible both to produce shaped and precise composite castings with saturated reinforcement and to consequently minimize machining losses. Metal-ceramic composites from the HMMC group are hard-to-machine materials which create problems during machining. The aim of these studies was to develop a laser engraving technology with Al matrix composite with the addition of Al2O3 particles and aluminosilicate fibers, which constitute the reinforcement. The focus was on the selection of engraving parameters (beam power and speed of movement of the laser head). Clear examples of engraving, suitable for macro-assessment, were obtained with minimal change in the initial surface structure of the composite.

Increased Amount of Polyunsaturated Fatty Acids in the Intestinal Contents of Patients with Morbid Obesity.

INTRODUCTION: Obesity is associated with disturbed gut microbiota homeostasis that translates into altered intestinal and blood metabolite profiles. The long-chain fatty acid (LCFA) may be absorbed in the intestine, but until now, their composition in intestinal contents of patients with obesity has not been studied. The aim of the present study was to verify whether obesity is related to any changes in fecal LCFA content and whether intestinal LCFA content may be associated with the health status of patients with obesity. METHODS: The fatty acid composition has been studied in stool samples obtained from 26 patients with morbid obesity and 25 lean subjects by gas chromatography-mass spectrometry. The dietary habits were assessed using the Food Frequency Questionnaire (FFQ-6). RESULTS: Our results show for the first time that lean subjects and patients with obesity differ in their stool LCFA profiles. The levels of most n-3 polyunsaturated fatty acids (PUFAs) and n-6 PUFAs were significantly higher in fecal samples from people with obesity than in those from lean controls. CONCLUSIONS: Based on the current knowledge, we have defined three hypotheses that may explain proving the cause-and-effect relationships observed differences in fecal LCFA profiles between patients with obesity and lean subjects. They may be related to alterations in fat digestion and/or LCFA absorption and diet. However, proving the cause-and-effect relationships requires further research.

Analysis of the risk factors for perioperative morbidity after laparoscopic revisional bariatric procedures: results from the multicenter Polish Revision Obesity Surgery Study.

BACKGROUND: The growing number of primary bariatric operations has led to an increase in demand for revision surgeries. Higher numbers of revisional operations are also observed in Poland, yet their safety and efficacy remain controversial because of a lack of current recommendations and guidelines. OBJECTIVE: To review risk factors influencing perioperative morbidity. METHODS: A retrospective study was conducted to analyze the results of surgical treatment among 12 Polish bariatric centers. Inclusion criteria were laparoscopic revisional bariatric surgeries and patients ≥18 years of age. The study included 795 patients, of whom 621 were female; the mean age was 47 years (range: 40-55 years). RESULTS: Perioperative morbidity occurred in 92 patients (11.6%) enrolled in the study, including 76 women (82.6%). The median age was 45 years (range: 39-54 years). Statistically significant risk factors in univariate logistic regression models for perioperative complications were the duration of obesity, revisional surgery after Roux-en-Y gastric bypass (RYGB) or adjustable gastric band (AGB), difference in body mass index before revisional surgery and the lowest achieved after primary surgery, and postoperative morbidity of the primary surgery as the cause for revisional bariatric surgery. These factors were included in the multivariate regression model. Revisional surgery after AGB (odds ratio [OR] = 2.18; 95% confidence interval [CI]: 1.28-3.69; P = .004), revisional surgery performed after RYGB (OR = 6.52; 95% CI: 1.98-21.49; P = .002), and revisions due to complication of the primary surgery (OR = 1.89; 95% CI: 1.06-3.34; P = .030) remained independent risk factors for perioperative morbidity. CONCLUSION: Revisional operations after RYGB or AGB and those performed because of postoperative morbidity after primary surgery as the main cause for revisional surgery were associated with a significantly increased risk of postoperative morbidity.

Human EXOG Possesses Strong AP Hydrolysis Activity: Implication on Mitochondrial DNA Base Excision Repair.

Most oxidative damage on mitochondrial DNA is corrected by the base excision repair (BER) pathway. However, the enzyme that catalyzes the rate-limiting reaction─deoxyribose phosphate (dRP) removal─in the multienzymatic reaction pathway has not been completely determined in mitochondria. Also unclear is how a logical order of enzymatic reactions is ensured. Here, we present structural and enzymatic studies showing that human mitochondrial EXOG (hEXOG) exhibits strong 5'-dRP removal ability. We show that, unlike the canonical dRP lyases that act on a single substrate, hEXOG functions on a variety of abasic sites, including 5'-dRP, its oxidized product deoxyribonolactone (dL), and the stable synthetic analogue tetrahydrofuran (THF). We determined crystal structures of hEXOG complexed with a THF-containing DNA and with a partial gapped DNA to 2.9 and 2.1 Šresolutions, respectively. The structures illustrate that hEXOG uses a controlled 5'-exonuclease activity to cleave the third phosphodiester bond away from the 5'-abasic site. This study provides a structural basis for hEXOG's broad spectrum of substrates. Further, we show that hEXOG can set the order of BER reactions by generating an ideal substrate for the subsequent reaction in BER and inhibit off-pathway reactions.

Tool Wear and Surface Roughness in Turning of Metal Matrix Composite Built of Al2O3 Sinter Saturated by Aluminum Alloy in Vacuum Condition.

Metal matrix composites (MMCs) are a special class of materials carrying combined properties that belongs to alloys and metals according to market demands. Therefore, they are used in different areas of industry, and the properties of this type of material are useful in engineering applications. Machining of such composites is of great importance to finalize the fabrication process with improved part quality. However, the process implies several challenges due to the complexity of the cutting processes and random material structure. The current study aims to examine machinability characteristics. Effects of turning a metal matrix composite built of Al2O3 sinter, saturated with an EN AC-44000 AC-AlSi11 alloy, are presented in this paper. In the present study, a turning process of new metal matrix composites was carried out to determine the state-of-the-art material for various engineering applications. During the turning process, the cutting forces, a tool's wear, and surface roughness were investigated. Further, the SEM (scanning electron microscope) analysis of cutting inserts was performed. The influence of MMC structure on the machining process and surface roughness was studied. The Al2O3 reinforcements were used in different graininess. Effects of conventional turning of the metal matrix composite with Al2O3 sinter of FEPA (Federation of European Producers of Abrasives) 046 and FEPA 100 grade were compared. Results analysis of these tests showed the necessity of continuing research on turning metal matrix composites built of an AlSi alloy and Al2O3 ceramic reinforcement. The study showed the properties of MMCs that influenced machinability. In this paper, the influence of feed rate's value on surface roughness was carried out. The significant tool wear during the turning of the MMC was proved.

Comparison of the Long-term Outcomes of RYGB and OAGB as Conversion Procedures After Failed LSG - a Case-Control Study.

OBJECTIVE: To compare the effect of RYGB and OAGB on patients after failed treatment of obesity by laparoscopic sleeve gastrectomy (LSG). STUDY DESIGN: A case-control study based on a prospectively maintained database of reoperated patients after failed LSG, which included 33 patients who underwent RYGB conversion and 47 patients who underwent OAGB conversion. RESULT: The mean %EBWL after a 5-year follow-up for RYGBc vs OAGBc was 84.04% vs 72.95% (p = 0.2176), respectively. Complete long-term diabetes remission was observed significantly more frequently in the OAGBc than in the RYGBc group (97.3% vs 33%; p = 0.035). There were no other statistically significant differences in the remission rate of comorbidities between RYGBc and OAGBc: hypertension 30% vs 27.3% (p = 0.261), dyslipidemia 83.3% vs 59.1% (p = 0.277), OSAS 100% vs 60% (p = 0.639), and GERD 40% vs 71.4% (p > 0.99), respectively. 7 patients were newly diagnosed with GERD after OAGBc and none after RYGBc. There were no statistically significant differences in the number of complications between the OAGBc and RYGB groups. The Comprehensive Complication Index was 17.85 (± IQR 29.6) in the OAGBc group and 14.92 (± IQR 21.75) in the RYGBc group (p = 0.375). CONCLUSION: The authors recognized complete long-term type 2 diabetes remission after conversion surgery as the most relevant difference, where the OAGB variety was found superior for its better efficacy. Any other statistically significant differences in the consequences after both conversion procedures used after the failure of LSG have not been stated. Both methods therefore can be considered to complete the initial treatment, considering the preferences and individual burdens of the patients.

In vitro reconstitution reveals a key role of human mitochondrial EXOG in RNA primer processing.

The removal of RNA primers is essential for mitochondrial DNA (mtDNA) replication. Several nucleases have been implicated in RNA primer removal in human mitochondria, however, no conclusive mechanism has been elucidated. Here, we reconstituted minimal in vitro system capable of processing RNA primers into ligatable DNA ends. We show that human 5'-3' exonuclease, EXOG, plays a fundamental role in removal of the RNA primer. EXOG cleaves short and long RNA-containing flaps but also in cooperation with RNase H1, processes non-flap RNA-containing intermediates. Our data indicate that the enzymatic activity of both enzymes is necessary to process non-flap RNA-containing intermediates and that regardless of the pathway, EXOG-mediated RNA cleavage is necessary prior to ligation by DNA Ligase III. We also show that upregulation of EXOG levels in mitochondria increases ligation efficiency of RNA-containing substrates and discover physical interactions, both in vitro and in cellulo, between RNase H1 and EXOG, Pol γA, Pol γB and Lig III but not FEN1, which we demonstrate to be absent from mitochondria of human lung epithelial cells. Together, using human mtDNA replication enzymes, we reconstitute for the first time RNA primer removal reaction and propose a novel model for RNA primer processing in human mitochondria.

The impact of the interplay of the intestinal microbiome and diet on the metabolomic and health outcomes of bariatric surgery.

Obesity has evolved into a global epidemic. Bariatric surgery, the most effective treatment for obesity, keeps many comorbidities of obesity at bay for a prolonged period of time. However, complications, including metabolic alterations, are inherent in bariatric surgery. Surgical intervention in the structure of the digestive tract, especially during bariatric bypass procedures, also causes significant changes in the composition of the microbiome, which may affect the composition and quantity of various metabolites produced by intestinal bacteria. The composition of the intestinal microbiome is connected to human metabolism via metabolites that are produced and secreted by bacterial cells into the intestinal lumen and then absorbed into the host's bloodstream. Bariatric surgery causes changes in the composition and quantity of many circulating metabolites. Metabolic disorders may be affected after bariatric surgery by changes in the composition of the microbiome and metabolites produced by bacteria.

Phenolic Composition of Inflorescences of Carduus nutans L.

Carduus nutans L. (Compositae) has been extensively used for medicinal purposes. As other representatives of the genus it is implemented in the treatment of liver disorders and used as diuretic and digestive agent. Previous studies have determined the predominant classes of secondary metabolites in Carduus species. Among the major representatives of their extracts flavonoids, phenolic acids, coumarins, sterols and terpenes were identified. The antiradical capacity of three extracts assessed in the DPPH test revealed the highest radical scavenging properties of methanol extract (the EC50 618±10.03 µg/mL) and based on these results it was selected for phenolic content determination. (TPC=61.49 mg/g). To understand better the induced pharmacological effects of the plant the aim of the study was to determine the composition of the methanol extract from the inflorescences of C. nutans and to study their phenolic composition. In order to determine the composition in a more efficient way, the crude extract was fractionated and subjected to hydrolyses. As a result more than twenty phenolic acids and flavonoids were identified in the extract and fractions by HPLC-DAD and/or HPLC-ESI-TOF-MS. The total extract was later subjected to fractionation by centrifugal partition chromatography using the Arizona system composed of hexane/ethyl acetate/methanol/water (0.7 : 4 : 0.8 : 4 v/v/v/v) to produce fractions enriched in flavonoids that are of high pharmacological significance.