An efficient method for constructing a random insertional mutant library for forward genetics in Nannochloropsis oceanica

Insertional mutation,phenotypic evaluation,and mutated gene cloning are widely used to clone genes from scratch.Exogenous genes can be integrated into the genome during non-homologous end joining(NHEJ)of the double-strand breaks of DNA,causing insertional mutation.The random insertional mutant library constructed using this method has become a method of forward genetics for gene cloning.However,the establishment of a random insertional mutant library requires a high transformation efficiency of exogenous genes.Many microalgal species show a low transformation efficiency,making constructing random insertional mutant libraries difficult.In this study,we established a highly efficient transformation method for constructing a random insertional mutant library of Nannochloropsis oceanica,and tentatively tried to isolate its genes to prove the feasibility of the method.A gene that may control the growth rate and cell size was identified.This method will facilitate the genetic studies of N.oceanica,which should also be a reference for other microalgal species.

T-DNA transfer and integration as a tool for insertional mutagenesis in the taxol-producing fungus

Agrobacterium tumefaciens-mediated DNA transiormation method was applied to transform Noclulisporium sylviforme fusant HDF-68, a taxol-produeing fungus. We constructed a binary vector pBI121-43 canting a hygromycin-resistant gene cassette between the right and left borders of T-DNA, Optimal co-cultivation of N.sylviforrne with A. tumefaciens containing pBI121-43 led to 110- 130 hygromycin-resistant transformants per＂ million eonidia. Putative transformants were found to be mitotically stable. The molecular analysis of transformants demonstrated the random integration of single copy of the T-DNA into the host genome. This transformation system serves as a basic tool for insertional mutagenesis in N. sylviforme fusant HDF-68, and the development of such svstem lays a solid foundation for constructing high-yied gene engineering strain and clarifying taxol biosynthesis pathway in this fungus.

Efficient isolation of specific genomic regions by insertional chromatin immunoprecipitation (iChIP) with a second-generation tagged LexA DNA-binding domain

Comprehensive understanding of mechanisms of epigenetic regulation requires identification of molecules bound to genomic regions of interest in vivo. We have developed a novel method, insertional chromatin immunoprecipitatin (iChIP), to isolate specific genomic regions retaining molecular interaction in order to perform non-biased identification of interacting molecules in vivo. Here, we developed a second-generation tagged LexA DNA-binding domain, 3xFNLDD, for the iChIP analysis. 3xFNLDD consists of 3 x FLAG tags, a nuclear localization signal (NLS), the DNA-binding domain (DB) and the dimerization domain of the LexA protein. Expression of 3xFNLDD can be detected by immunoblot analysis as well as flowcytometry. We showed that iChIP using 3xFNLDD is able to consistently isolate more than 10% of input genomic DNA, several-fold more efficient compared to the first-generation tagged LexA DB. 3xFNLDD would be a useful tool to perform the iChIP analysis for locus-specific biochemical epigenetics.

Ultrasound and Color Doppler-Guided Surgery for Insertional Achilles Tendinopathy-Results of a Pilot Study

Background: Treatment of insertional achilles tendinopathy is known to be difficult. Eccentric calf muscle exercises and extracorporeal shockwave therapy have been proposed as the primary treatments for this condition, but surgery is indicated after failed conservative management. There is no consensus about the most efficient surgical treatment. Objectives: To evaluate a new ultrasound and color Doppler-guided surgical treatment for insertional achilles tendinopathy. Patients and methods: 24 consecutive patients (13 men and 11 women, mean age 47 years) with a long duration of insertional achilles tendon pain (median 18 months) were included in the study. The surgical procedure consisted of extirpation of the subcutaneous and retrocalcaneal bursa, scraping of the ventral distal achilles tendon and removal of prominent bone at the upper calcaneal tuberosity (Haglund’s deformity). In 13 patients, the plantaris tendon was also cut and excised. VAS for pain during activity, satisfaction with the treatment result and the SF-36 score to measure quality of life were used for evaluation. Results: The mean VAS had decreased from 72 before surgery to 19 after surgery (p 0.001), and 20/24 (83%) patients were satisfied with the result and had returned to full tendon loading activity at the one-year follow-up. The SF-36 score had improved significantly. Conclusion: Ultrasound and color Doppler-guided surgical treatment seems to be a good method for treatment of chronic painful insertional achilles tendinopathy. Longer follow-up studies on larger materials are needed.

Isolation of T-DNA flanking plant DNA from T-DNAinsertional embryo-lethal mutants of Arabidopsis thaliana by plasmid rescue technique

Three T-DNA insertional embryonic lethal mutants from NASC (The Nottingham Arabidopsis Stock Center)were first checked with their segregation ratio of abortive and normal seeds and the copy number of T-DNA insertion. The N4081 mutant has a segregation ratio of 1:3.04in average and one T-DNA insertion site according to our assay It was therefore chosen for further analysis. To isolate the joint fragment of T-DNA and plan DNA, the plasmid rescue technique waJs used. pEL-7, one of plasmids from left border of T-DNA, which contained pBR322 was selected from ampicillin plate. The T-DNA fragment of pEL-7 was checked by restriction enzyme analysis and Southern Blot. Restriction analysis confirmed the presence of known sites of EcoRI, PstI and PvuII on it.For confirming the presence of flanking plant DNA in this plasmid, pEL-7 DNA was labeled and hybridized with wild type and mutant plant DNA. The Southern Blot indicated the hybridization band in both of them. Furthermore, the junction of T-DNA/plant DNA was subcloned into bluescript SK+ and sequenced by Applied Biosystem 373A Sequencer. The results showed the 822 bp fragment contained a 274 bp sequence, which is 99.6%homolog (273bp/274 bp) to Ti plasmid pTi 15955 DNA.Ten bp of left 25 bp border repeat were also found in the juction of T-DNA and Plant DNA.Taken together, pEL-7 should contain a joint fragment of T-DNA and flanking plant DNA. This plasmid DNA could be used for the isolation of plant gene, which will be helpful to elucidate the relationship between gene function and plant embryo development.

Isolating the Mutator Transposable Element Insertional Mutant Gene mio16 of Maize Using Double SelectedAmplification of Insertion Flanking Fragments (DSAIFF)

Mutator transposable element （Mu） has been used as an effective tool to clone maize （Zea mays L.） genes. One opaque endosperm mutant （miol6） was identified in a pool of Mu inserted mutants. A modified method, termed the double selected amplification of insertion flanking fragments （DSAIFF）, was employed to isolate the Mu flanking fragments （MFFs） of miol6. The target site duplications （TSDs） isolated from the Msp I and Mse I digested MFFs had a same 9-bp sequence and were confirmed to be the flanking sequence of one identically inserted gene. Co-segregation analysis suggested that the MFFs were associated with the mutant opaque endosperm, and miol6 was mapped in silico onto the physical position ranged from 229 965 021 to 229 965 409 bp of the maize chromosome 4.09 bin. The full-length cDNA of the wild-type gene was obtained by an RT-PCR primer-scanning technique, and Mio16 was found to putatively encode a homolog of the Arabidopsis MAP3K delta-1 protein kinase. RT-PCR result the mRNA expression of miol6 region anchored by primers Mu20 and af276 was not interrupted by Mu insertion. Further researches will be done to elucidate how the expression of miol6 is alternated by Mu insertion.

A 9.5-kb deletion in the 1st intron of OsMADS51 enhances temperature sensitivity in rice

Temperature is an important environmental factor affecting heading date of rice.Despite its importance,genes responsible for temperature-sensitive heading in rice have remained elusive.Our previous study identified a quantitative trait locus qHd1 which advances heading date under high temperatures.A 9.5-kb insertion was found in the first intron of OsMADS51 in indica variety Zhenshan 97(ZS97).However,the function of this natural variant in controlling temperature sensitivity has not been verified.In this study,we used CRISPR/Cas9 to knock out the 9.5-kb insertion in ZS97.Experiments conducted under cotrolled conditions in phytotrons confirmed that deletion increased temperature sensitivity and advanced heading by downregulating the expression level of OsMADS51.One-hybrid assays in yeast,ChIP-quantitative polymerase chain reaction,electrophoretic mobility shift,and luciferase-based transient transactivation assays collectively confirmed that OsMADS51 affects heading date by regulation of heading date gene Ehd1.We further determined that the long non-coding RNA HEATINR is generated from the first intron of OsMADS51,offering an explanation for how the 9.5-kb insertion affects temperature sensitivity.We also found that OsMADS51 was strongly selected in early/late-season rice varieties in South China,possibly accounting for their strong temperature sensitivity.These insights not only advance our understanding of the molecular mechanisms underlying the temperature-responsive regulation of heading date in rice but also provide a valuable genetic target for molecular breeding.

Establishment and validation of a predictive model for peripherally inserted central catheter-related thrombosis in patients with liver cancer

BACKGROUND Peripherally inserted central catheters(PICCs)are commonly used in hospitalized patients with liver cancer for the administration of chemotherapy,nutrition,and other medications.However,PICC-related thrombosis is a serious complication that can lead to morbidity and mortality in this patient population.Several risk factors have been identified for the development of PICC-related thrombosis,including cancer type,stage,comorbidities,and catheter characteristics.Understanding these risk factors and developing a predictive model can help healthcare providers identify high-risk patients and implement preventive measures to reduce the incidence of thrombosis.AIM To analyze the influencing factors of PICC-related thrombosis in hospitalized patients with liver cancer,construct a predictive model,and validate it.METHODS Clinical data of hospitalized patients with liver cancer admitted from January 2020 to December 2023 were collected.Thirty-five cases of PICC-related thrombosis in hospitalized patients with liver cancer were collected,and 220 patients who underwent PICC placement during the same period but did not develop PICC-related thrombosis were randomly selected as controls.A total of 255 samples were collected and used as the training set,and 77 cases were collected as the validation set in a 7:3 ratio.General patient information,case data,catheterization data,coagulation indicators,and Autar Thrombosis Risk Assessment Scale scores were analyzed.Univariate and multivariate unconditional logistic regression analyses were performed on relevant factors,and the value of combined indicators in predicting PICC-related thrombosis in hospitalized patients with liver cancer was evaluated using receiver operating characteristic(ROC)curve analysis.RESULTS Univariate analysis showed statistically significant differences(P<0.05)in age,sex,Karnofsky performance status score(KPS),bedridden time,activities of daily living impairment,parenteral nutrition,catheter duration,distant metastasis,and bone marrow suppression between the thrombosis group and the non-thrombosis group.Other aspects had no statistically significant differences(P>0.05).Multivariate regression analysis showed that age≥60 years,KPS score≤50 points,parenteral nutrition,stage III to IV,distant metastasis,bone marrow suppression,and activities of daily living impairment were independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer(P<0.05).Catheter duration of 1-6 months and catheter duration>6 months were protective factors for PICC-related thrombosis(P<0.05).The predictive model for PICC-related thrombosis was obtained as follows:P predictive probability=[exp(Logit P)]/[1+exp(Logit P)],where Logit P=age×1.907+KPS score×2.045+parenteral nutrition×9.467+catheter duration×0.506+tumor-node-metastasis(TNM)staging×2.844+distant metastasis×2.065+bone marrow suppression×2.082+activities of daily living impairment×13.926.ROC curve analysis showed an area under the curve(AUC)of 0.827(95%CI:0.724-0.929,P<0.001),with a corresponding optimal cut-off value of 0.612,sensitivity of 0.755,and specificity of 0.857.Calibration curve analysis showed good consistency between the predicted occurrence of PICC-related thrombosis and actual occurrence(P>0.05).ROC analysis showed AUCs of 0.888 and 0.729 for the training and validation sets,respectively.CONCLUSION Age,KPS score,parenteral nutrition,TNM staging,distant metastasis,bone marrow suppression,and activities of daily living impairment are independent risk factors for PICC-related thrombosis in hospitalized patients with liver cancer,while catheter duration is a protective factor for the disease.The predictive model has an AUC of 0.827,indicating high predictive accuracy and clinical value.

Lower extremity peripherally inserted central catheter placement ectopic to the ascending lumbar vein:A case report

BACKGROUND Peripherally inserted central catheters(PICCs)are an essential infusion route for oncology patients receiving intravenous treatments,but lower extremity veni-puncture is the preferred technique for patients with superior vena cava syndrome(SVCS).We report the case of a patient with a lower extremity PICC ectopic to the ascending lumbar vein,to indicate and verify PICC catheterisation in the lower extremity is safe and feasible.And hope to provide different per-spectives for clinical PICC venipuncture to get the attention of peers.CASE SUMMARY On 24 August 2022,a 58-year-old male was admitted to our department due to an intermittent cough persisting for over a month,which worsened 10 d prior.Imaging and laboratory investigations suggested the patient with pulmonary malignancy and SVCS.Chemotherapy was not an absolute contraindication in this patient.Lower extremity venipuncture is the preferred technique because administering upper extremity venous transfusion to patients with SVCS can exacerbate oedema in the head,neck,and upper extremities.The patient and his family were informed about the procedure,and informed consent was obtained.After successful puncture and prompt treatment,the patient was discharged,experiencing some relief from symptoms.CONCLUSION Inferior vena cava catheterisation is rare and important for cancer patients with SVCS,particularly in complex situations involving ectopic placement.

A Novel Insertion Solution for the Travelling Salesman Problem

The studypresents theHalfMax InsertionHeuristic (HMIH) as a novel approach to solving theTravelling SalesmanProblem (TSP). The goal is to outperform existing techniques such as the Farthest Insertion Heuristic (FIH) andNearest Neighbour Heuristic (NNH). The paper discusses the limitations of current construction tour heuristics,focusing particularly on the significant margin of error in FIH. It then proposes HMIH as an alternative thatminimizes the increase in tour distance and includes more nodes. HMIH improves tour quality by starting withan initial tour consisting of a ‘minimum’ polygon and iteratively adding nodes using our novel Half Max routine.The paper thoroughly examines and compares HMIH with FIH and NNH via rigorous testing on standard TSPbenchmarks. The results indicate that HMIH consistently delivers superior performance, particularly with respectto tour cost and computational efficiency. HMIH’s tours were sometimes 16% shorter than those generated by FIHand NNH, showcasing its potential and value as a novel benchmark for TSP solutions. The study used statisticalmethods, including Friedman’s Non-parametric Test, to validate the performance of HMIH over FIH and NNH.This guarantees that the identified advantages are statistically significant and consistent in various situations. Thiscomprehensive analysis emphasizes the reliability and efficiency of the heuristic, making a compelling case for itsuse in solving TSP issues. The research shows that, in general, HMIH fared better than FIH in all cases studied,except for a few instances (pr439, eil51, and eil101) where FIH either performed equally or slightly better thanHMIH. HMIH’s efficiency is shown by its improvements in error percentage (δ) and goodness values (g) comparedto FIH and NNH. In the att48 instance, HMIH had an error rate of 6.3%, whereas FIH had 14.6% and NNH had20.9%, indicating that HMIH was closer to the optimal solution. HMIH consistently showed superior performanceacross many benchmarks, with lower percentage error and higher goodness values, suggesting a closer match tothe optimal tour costs. This study substantially contributes to combinatorial optimization by enhancing currentinsertion algorithms and presenting a more efficient solution for the Travelling Salesman Problem. It also createsnew possibilities for progress in heuristic design and optimization methodologies.

Enhancing hydrogen evolution and oxidation kinetics through oxygen insertion into nickel lattice

Nickel-based materials,including metallic Ni and Ni oxide,have been widely studied in the exploration of non-precious-metal hydrogen electrocatalysts,but neither pure Ni nor NiO is ideal for the hydrogen evolution reaction(HER)and hydrogen oxidation reaction(HOR).In this paper,an oxygen insertion strategy was applied on nickel to regulate its hydrogen electrocatalytic performance,and the oxygen-inserted nickel catalyst was successfully obtained with the assistance of tungsten dioxide support(denoted as O-Ni/WO_(2)).The partial insertion of oxygen in Ni maintains the face-centered cubic arrangement of Ni atoms,simultaneously expanding the lattice and increasing the lattice spacing.Consequently,the adsorption strength of^(*)H and^(*)OH on Ni is optimized,thus resulting in superior electrocatalytic performance of0-Ni/WO_(2)in alkaline HER/HOR.The Tafel slope of O-Ni/WO_(2)@NF for HER is 56 mV dec^(-1),and the kinetic current density of O-Ni/WO_(2)for HOR reaches 4.85 mA cm^(-2),which is ahead of most currently reported catalysts.Our proposed strategy of inserting an appropriate amount of anions into the metal lattice could provide more possibilities for the design of high-performance catalysts.

Esophageal inserted subclavian catheter:a rare complication

Central venous catheterization(CVC) is an invasive procedure for administering fluids,nutrients,and drugs;monitoring central venous pressure;performing pulmonary artery catheterization;and placing transvenous pacemakers in intensive care units and all specialties,from anesthesia to emergency medicine,for the treatment of trauma and hemodynamically unstable pediatric and adult patients.[1,2]Complications have been observed in more than 15% of patients who underwent CVC.Mechanical,infectious,and thrombotic complications have been reported in 5%–19%,5%–26%,and 2%–26% of patients,respectively.[3] Malposition,on the other hand,is common in subclavian catheter insertion and is usually associated with an initially misplaced guidewire.[4]

Identification and characterization of FpRco1 in regulating vegetative growth and pathogenicity based on T-DNA insertion in Fusarium pseudograminearum

Fusarium pseudograminearum is a devastating pathogen that causes Fusarium crown rot(FCR)in wheat and poses a significant threat to wheat production in terms of grain yield and quality.However,the mechanism by which F.pseudograminearum infects wheat remains unclear.In this study,we aimed to elucidate these mechanisms by constructing a T-DNA insertion mutant library for the highly virulent strain WZ-8A of F.pseudograminearum.By screening this mutant library,we identified nine independent mutants that displayed impaired pathogenesis in barley leaves.Among these mutants,one possessed a disruption in the gene FpRCO1 that is an ortholog of Saccharomyces cerevisiae RCO1,encoding essential component of the Rpd3S histone deacetylase complex in F.pseudograminearum.To further investigate the role of FpRCO1 in F.pseudograminearum,we employed a split-marker approach to knock out FpRCO1 in F.pseudograminearum WZ-8A.FpRCO1 deletion mutants exhibit reduced vegetative growth,conidium production,and virulence in wheat coleoptiles and barley leaves,whereas the complementary strain restores these phenotypes.Moreover,under stress conditions,the FpRCO1 deletion mutants exhibited increased sensitivity to NaCl,sorbitol,and SDS,but possessed reduced sensitivity to H_(2)O_(2)compared to these characteristics in the wild-type strain.RNA-seq analysis revealed that deletion of FpRCO1 affected gene expression(particularly the downregulation of TRI gene expression),thus resulting in significantly reduced deoxynivalenol(DON)production.In summary,our findings highlight the pivotal role of FpRCO1 in regulating vegetative growth and development,asexual reproduction,DON production,and pathogenicity of F.pseudograminearum.This study provides valuable insights into the molecular mechanisms underlying F.pseudograminearum infection in wheat and may pave the way for the development of novel strategies to combat this devastating disease.

Reversible Optical Isolators and Quasi-Circulators Using a Magneto-Optical Fabry-Pérot Cavity

Nonreciprocal optical devices are essential for laser protection,modern optical communication and quantum information processing by enforcing one-way light propagation.The conventional Faraday magneto-optical nonreciprocal devices rely on a strong magnetic field,which is provided by a permanent magnet.As a result,the isolation direction of such devices is fixed and severely restricts their applications in quantum networks.In this work,we experimentally demonstrate the simultaneous one-way transmission and unidirectional reflection by using a magneto-optical Fabry-Pérot cavity and a magnetic field strength of 50 mT.An optical isolator and a three-port quasi-circulator are realized based on this nonreciprocal cavity system.The isolator achieves an isolation ratio of up to 22 dB and an averaged insertion loss down to 0.97 dB.The quasi-circulator is realized with a fidelity exceeding 99% and an overall survival probability of 89.9%,corresponding to an insertion loss of~0.46 dB.The magnetic field is provided by an electromagnetic coil,thereby allowing for reversing the light circulating path.The reversible quasi-circulator paves the way for building reconfigurable quantum networks.

Appropriate Combination of Crossover Operator and Mutation Operator in Genetic Algorithms for the Travelling Salesman Problem

Genetic algorithms(GAs)are very good metaheuristic algorithms that are suitable for solving NP-hard combinatorial optimization problems.AsimpleGAbeginswith a set of solutions represented by a population of chromosomes and then uses the idea of survival of the fittest in the selection process to select some fitter chromosomes.It uses a crossover operator to create better offspring chromosomes and thus,converges the population.Also,it uses a mutation operator to explore the unexplored areas by the crossover operator,and thus,diversifies the GA search space.A combination of crossover and mutation operators makes the GA search strong enough to reach the optimal solution.However,appropriate selection and combination of crossover operator and mutation operator can lead to a very good GA for solving an optimization problem.In this present paper,we aim to study the benchmark traveling salesman problem(TSP).We developed several genetic algorithms using seven crossover operators and six mutation operators for the TSP and then compared them to some benchmark TSPLIB instances.The experimental studies show the effectiveness of the combination of a comprehensive sequential constructive crossover operator and insertion mutation operator for the problem.The GA using the comprehensive sequential constructive crossover with insertion mutation could find average solutions whose average percentage of excesses from the best-known solutions are between 0.22 and 14.94 for our experimented problem instances.

Tubular Heat Enhancement Using Twisted Tape Inserts with Large Holes

Heat augmentation techniques play a vital role in the heating and cooling processes in industries,including solar collectors and many applications that utilize heat exchangers.Several studies are based on inserting fillers inside the tubes to enhance heat transfer.This investigation considered the effects of twisted tapes with large holes on a tubular heat exchanger’s(HX)heat transmission,pressure drop,and thermal boosting factor.In the experimental section,counter-swirl flow generators used twisted tapes with pairs of 1.0 cm-diameter holes and changes in porosity(Rp)at 1.30%and 2.70%.In the experiments,air was utilized as a working fluid in a tube with a circular cross-section.The turbulent flow was considered,with Reynolds numbers(Re)domain from 4800 to 9500,and a boundary condition with a uniform wall heat flux was constructed.The findings expound that when the number of holes rose,the Nusselt number(Nu),the factor of friction(f),and the thermal enhancement factor(η)all increased as well.Additionally,as the friction factor increased,the Nusselt number of the tape-equipped tube was noticeably higher.Additionally,it was discovered that the friction factor was between 70%and 94%lower than the values of the tube without tape,while the(Nu)was between 87%and 97%higher than the conventional tube values.The maximum value ofηis 89%.According to the experimental results,empirical correlations for Nu,f,andηwere also generated.

Dual-chamber pacing confers better myocardial performance and improves clinical outcomes compared to single-chamber pacing

The deleterious effects of long term right ventricular pacing are increasingly being recognized today.Current clinical practice favors the implantation of dual-chamber permanent pacemaker which maintains atrioventricular synchrony and is associated with better quality of life.However,despite the popular belief and common sense surrounding the superiority of dual-chamber pacing over single chamber pacing,the same has never been conclusively verified in clinical trials.Some observational evidence however,does exists which supports the improved cardiac hemodynamics,lower the rate of atrial fibrillation,heart failure and stroke in dual-chamber pacing compared to single-chamber pacing.In the index study by Haque et al,right ventricular pacing,particularly in ventricular paced,ven-tricular sensed,inhibited response and rate responsive pacemaker adversely im-pacted the left ventricular functions over 9-months compared to dual pacing,dual sensing,dual responsive and rate responsive pacemaker.Although there are key limitations of this study,these findings does support a growing body of evidence reinstating the superiority of dual chamber pacing compared to single chamber pacing.

Treatment of benign rectal stricture caused by repeated anal insertion by endoscopy and balloon dilation:A case report

BACKGROUND Benign rectal strictures can be categorized as primary(disease-related)and secondary(surgical anastomosis-related).Secondary strictures arise from surgical complications,whereas primary strictures have diverse etiologies,including various inflammatory conditions.Benign strictures are usually managed by surgery and endoscopy.We present an unusual etiology of benign rectal stricture caused by the repeated insertion of foreign objects into the rectum for sexual purposes,resulting in rectal injury and subsequent chronic inflammation.CASE SUMMARY A 53-year-old man presented to the outpatient clinic of the Colorectal Surgery Department with symptoms of chronic constipation and bloody stools.The patient previously experienced rectal injury due to foreign object insertion for sexual purposes.Colonoscopy revealed benign circumferential narrowing of the rectum.He underwent treatment by endoscopic argon plasma coagulation and balloon dilation and follow-up as an outpatient for 4 months.A colonoscopy at the end of the follow-up period revealed no evidence of rectal stricture relapse.CONCLUSION A history of rectal injury,followed by chronic inflammation,should be considered in patients with benign rectal strictures.Management with endoscopic argon plasma coagulation and balloon dilation can prevent the need for surgical resection of benign rectal strictures.

Investigation of Fracture Strength of Current Post Materials (Peek, Fiber, Cast Metal) in Different Ferrule Conditions

Aim: The fracture resistance of the post materials used nowadays significantly impacts the fracture type of the post material. The current study aimed to examine the impact of the fracture resistance of PEEK posts, whose use as a post material has not yet become widespread, on the fracture pattern that will occur. Materials and Methods: Sixty-six extracted upper central incisor human teeth were used in the study. Six groups of posts were produced from metal, fiber, and PEEK materials (n = 11). Afterward, the fracture resistance test was applied to the samples. Samples were classified according to fracture type as repairable or irreparable. The ANOVA and test were used in statistical analysis. Post-hoc tests were carried out using Tukey’s and Tamhane’s T2 tests. On the other hand, Pearson’s chi-square test and the Fisher-Freeman-Halton test were conducted for comparisons between categorical variables. The statistical significance level was accepted as p Results: According to the fracture resistance test results, the groups where metal personal posts were used displayed higher fracture resistance in comparison with all other groups. According to the results of the optical microscope examination, the incidence of repairable fractures was significantly higher in the PEEK post group with ferrule preparation (p 0.05). Conclusion: In the absence of the ferrule effect, fractures are catastrophic, regardless of the material used. The use of PEEK as a post material contributes to keeping fractures at a repairable level.

Current Topics in Acute Abdomen: Causes, Diagnostics, and Emerging Therapies

Acute abdomen is a serious clinical condition that requires immediate attention due to its association with intense pain and rapid progression. This article reviews important aspects of the causes, diagnostics, and treatments of acute abdomen. The research highlights the diversity of etiologies, ranging from the most common, such as acute appendicitis, to the less frequent, such as intestinal perforations by foreign bodies. Complex diagnostic methods, including clinical examinations and imaging such as computed tomography, are essential to guide accurate diagnosis, given the overlap of symptoms among different conditions. Therapeutic approaches range from conservative treatments with clinical observation and antibiotic therapy to urgent surgical interventions, such as appendectomy and cholecystectomy. Laparoscopy stands out as a promising approach, offering advantages in terms of recovery and post-operative morbidity. However, the impact of the COVID-19 pandemic has brought additional challenges to the diagnosis and treatment of acute abdomen, with delays and difficulties in accessing healthcare. This review underscores the importance of a multidisciplinary approach and constant updates among healthcare professionals in addressing acute abdomen, aiming for accurate diagnoses and appropriate therapeutic interventions to improve clinical outcomes and reduce morbidity and mortality associated with this complex clinical condition.