Comparison of three umbilical entry sites for intraperitoneal access by the direct trocar insertion technique: a randomized pilot study.

Objective: The most effective methods and entry sites for laparoscopic surgery remain a subject of ongoing investigation and discussion. The purpose of the study was to analyze and compare three umbilical entry sites for intraperitoneal access using the direct trocar insertion technique. Material and Methods: A randomized pilot study was conducted between March 2021 and January 2023, involving women eligible for laparoscopic gynecological surgery. The women were allocated to one of three equally sized groups based on trocar entry points: subumbilical, supraumbilical, or umbilical. Success and failure rates of trocar entry, factors influencing success or failure, and early and late complications were systematically evaluated and compared across groups. Results: A total of 243 patients, with a mean age of 32.93±8.33 years, were included in three groups of 81 each. Trocar entry success rates were 97.5%, 89.2%, and 89.5% in the supraumbilical, umbilical, and subumbilical groups, respectively (p>0.05). Failed trocar entry was significantly associated with age, gravidity, body mass index (BMI), waist circumference, hip circumference, and abdominal subcutaneous fat thickness (p<0.001). Regression analysis revealed that, in the subumbilical group, higher gravidity [odds ratios (OR): 0.390, 95% confidence interval (CI): 0.174-0.872, p=0.022) and greater abdominal subcutaneous fat thickness (OR: 0.090, 95% CI: 0.019-0.431, p=0.03) were associated with lower odds of successful trocar entry. In contrast, in the umbilical group, a higher waist circumference was associated with lower odds of successful trocar entry (OR: 0.673, 95% CI: 0.494-0.918, p=0.012). None of the covariates were significant in the supraumbilical group. Conclusion: The study highlighted the importance of selecting the appropriate trocar entry site in laparoscopic gynecological surgery. Surgeons should consider factors such as age, gravidity, BMI, waist circumference, hip circumference, and abdominal subcutaneous fat thickness, as these factors significantly influence the success of trocar entry.

InDel mutations within the bovine PER2 gene are significantly associated with reproductive traits.

Functioning as a key regulator of circadian rhythms, the PER2 gene exerts a substantial impact on the reproductive traits of animals. However, the effect of the PER2 gene on ovarian development remains unclear. In order to examine the relationship between bovine reproductive trait and the PER2 gene, a total of 901 ovarian samples were collected, categorized into different oestrus cycles (proestrus, oestrus, post-oestrus, anoestrous), and subjected to analysis for two potential insertion/deletions (InDels) in the PER2 gene. Through agarose gel electrophoresis and DNA sequencing, two polymorphic deletion mutations (P2-D5-bp, P3-D13-bp) were identified. Furthermore, a significant association between mature follicle diameter and P2-D5-bp was found (P < 0.05). Additionally, several significant correlations with ovarian length, width, height, and white body diameter were found for P3-D13-bp (P < 0.05). These findings suggested that the bovine PER2 gene plays an important role in above-mentioned reproductive traits, offering new avenues for improving cow fertility through marker-assisted selection (MAS).

A nisin-inducible chromosomal gene expression system based on ICE Tn5253 of Streptococcus pneumoniae, transferable among streptococci and enterococci.

The present work reports the development and validation of a chromosomal expression system in Streptococcus pneumoniae which permits gene expression under the control of Lactococcus lactis lantibiotic nisin. The system is based on the integrative and conjugative element (ICE) Tn5253 of S. pneumoniae capable of site-specific chromosomal integration and conjugal transfer to a variety of bacterial species. We constructed an insertion vector that integrates in Tn5251, an ICE contained in Tn5253, which carries the tetracycline resistance tet(M) gene. The vector contains the nisRK regulatory system operon, the L. lactis nisin inducible promoter PnisA upstream of a multiple cloning site for target DNA insertion, and is flanked by two DNA regions of Tn5251 which drive homologous recombination in ICE Tn5253. For system evaluation, the emm6.1::ha1 fusion gene was cloned and integrated into the chromosome of the Tn5253-carrying pneumococcal strain FR24 by transformation. This gene encodes a fusion protein containing the signal peptide, the 122 N-terminal and the 140 C-terminal aa of the Streptococcus pyogenes M6 surface protein joined to the HA1 subunit of the influenza virus A hemagglutinin. Quantitative RT-PCR analysis carried out on total RNA purified from nisin treated and untreated cultures showed an increase in emm6.1::ha1 transcript copy number with growing nisin concentration. The expression of M6-HA1 protein was detected by Western blot and quantified by Dot blot, while Flow cytometry analysis confirmed the presence on the pneumococcal surface. Recombinant ICE Tn5253::[nisRK]-[emm6.1::ha1] containing the nisin-inducible expression system was successfully transferred by conjugation in different streptococcal species including Streptococcus gordonii, S. pyogenes, Streptococcus agalactiae and Enterococcus faecalis. As for S. pneumoniae, the emm6.1::ha1 transcript copy number and the amount of M6-HA1 protein produced correlated with the nisin concentration used for induction in all investigated bacterial hosts. We demonstrated that this host-vector expression system is stably integrated as a single copy within the bacterial chromosome, is transferable to both transformable and non transformable bacterial species, and allows fine tuning of protein expression modulated by nisin concentration. These characteristics make our system suitable for a wide range of applications including complementation assays, physiological studies, host-pathogen interaction studies.

Impact of the nail insertion angle on the wedge effect in intramedullary nail fixation of intertrochanteric hip fractures.

BACKGROUND: The wedge effect is known to be influenced by the insertion of the proximal femoral intramedullary nail through the fracture line and the large proximal diameter of the nail. However, the impact of the nail insertion angle (NIA) on the wedge effect remains unclear. This study aimed to investigate: (1) how to evaluate the NIA intraoperatively, (2) whether the NIA is associated with the wedge effect, (3) whether the NIA can serve as a reliable predictor of the wedge effect, (4) which factors affect the NIA, and (5) which surgical techniques can prevent the occurrence of the wedge effect associated with the NIA. HYPOTHESIS: We hypothesized that an excessive NIA is related to the wedge effect and that lateral deviation of the entry point is associated with an excessive NIA. PATIENTS AND METHODS: Intraoperative fluoroscopy images of patients who underwent intramedullary nail fixation for intertrochanteric hip fractures between 2013 and 2023 were analyzed. NIA and insertion point distance (IPD) were measured on hip anteroposterior radiographs with the guidewire inserted. Femoral shaft lateralization (FSL) and neck-shaft angle (NSA) were measured on hip anteroposterior radiographs before and after nail insertion; differences in FSL and NSA were calculated. A negative difference in FSL combined with a positive difference in NSA indicated the occurrence of the wedge effect. Pearson's correlation test was used to determine relationships between continuous variables (NIA, FSL, NSA, and IPD). Binary logistic regression analyzed the association between NIA and the wedge effect. Receiver operating characteristic (ROC) curve analysis was used to determine the threshold value of NIA, with predictive performance assessed using the area under the ROC curve (AUC). Other potential factors influencing the wedge effect were also examined. RESULTS: A total of 408 patients were included. The mean NIA was 15.61 ± 4.49 °. Post-nail insertion, the average increase in FSL was 3.20 mm, and the average decrease in NSA was 1.90 °. Pearson's correlation test revealed that NIA was negatively correlated with the difference in FSL (R = 0.565, P < 0.001) and positively correlated with the difference in NSA (R = 0.509, P < 0.001). Binary logistic regression showed a significant correlation between NIA and the wedge effect (P < 0.001). ROC analysis indicated that the AUC for NIA was 0.813, with an optimal cutoff point of 14.85 °. IPD was positively correlated with NIA (R = 0.519, P < 0.001). Unstable fractures were associated with increased lateralization of the femoral shaft after nail insertion (P = 0.003). DISCUSSION: The NIA is positively correlated with the wedge effect in intramedullary nail fixation of intertrochanteric hip fractures. The wedge effect tends to occur when the NIA is >14.85 °, particularly in unstable fractures. Lateral deviation of the entry point is associated with an excessive NIA. Adducting the affected limb, moving the entry point slightly medial and using a medial pusher may help control the NIA to less than 14.85 ° to reduce the wedge effect. LEVEL OF EVIDENCE: III.

Assessment of lesion insertion tool in pelvis PET/MR data with applications to attenuation correction method development.

BACKGROUND: In modern positron emission tomography (PET) with multi-modality imaging (e.g., PET/CT and PET/MR), the attenuation correction (AC) is the single largest correction factor for image reconstruction. One way to assess AC methods and other reconstruction parameters is to utilize software-based simulation tools, such as a lesion insertion tool. Extensive validation of these simulation tools is required to ensure results of the study are clinically meaningful. PURPOSE: To evaluate different PET AC methods using a synthetic lesion insertion tool that simulates lesions in a patient cohort that has both PET/MR and PET/CT images. To further demonstrate how lesion insertion tool may be used to extend knowledge of PET reconstruction parameters, including but not limited to AC. METHODS: Lesion quantitation is compared using conventional Dixon-based MR-based AC (MRAC) to that of using CT-based AC (CTAC, a "ground truth"). First, the pre-existing lesions were simulated in a similar environment; a total of 71 lesions were identified in 18 pelvic PET/MR patient images acquired with a time-of-flight simultaneous PET/MR scanner, and matched lesions were inserted contralaterally on the same axial slice. Second, synthetic lesions were inserted into four anatomic target locations in a cohort of four patients who didn't have any observed clinical lesions in the pelvis. RESULTS: The matched lesion insertions resulted in unity between the lesion error ratios (mean SUVs), demonstrating that the inserted lesions successfully simulated the original lesions. In the second study, the inserted lesions had distinct characteristics by target locations and demonstrated negative max-SUV%diff trends for bone-dominant sites across the patient cohort. CONCLUSIONS: The current work demonstrates that the applied lesion insertion tool can simulate uptake in pelvic lesions and their expected SUV values, and that the lesion insertion tool can be extended to evaluate further PET reconstruction corrections and algorithms and their impact on quantitation accuracy and precision.

Impact of Oropharyngeal Stimulation during Laryngeal Mask Insertion on Cardiovascular Response in adult patients. A Double-blind Clinical Trial Study.

Objective: Laryngeal mask airway (LMA) insertion has been found to reduce cardiovascular responses when compared to laryngoscopy and intubation. This research aimed to examine the impact of various techniques employed for LMA insertion on cardiovascular response. Methods: This randomized, double-blind clinical trial included 90 elective surgery candidates divided into three groups of 30. All patients underwent similar anesthesia. The LMA was inserted using the classical technique, 180° rotation technique, and face-to-face triple maneuver technique (FFTMT). The cardiovascular responses, the success rate of LMA placement, and other outcomes were documented and compared among the three methods. Results: The study revealed that the blood pressure of patients 10 minutes after LMA insertion using the rotational technique was higher than the standard technique (p=0.019). The pulse rate in the third (p=0.044, p=0.024) and fifth minutes (p=0.028, p=0.048) following the insertion of LMA demonstrated higher values when utilizing the FFTMT than the standard and rotational technique groups, respectively. Moreover, the incidence of sore throat following surgery in the FTFTM group was slightly greater than that observed with the standard and rotation techniques (p=0.389 and p=0.688, respectively). Conclusion: The findings of the present investigation indicated that implementing the classic technique for LMA placement resulted in a more consistent blood pressure (BP) and pulse rate (PR) response than the 180° rotation and FFTMT. Furthermore, the classical method exhibited a marginally lower success rate in terms of LMA insertion than the alternative methods.

Critical tasks and errors associated with intercostal chest drain insertion.

INTRODUCTION: To describe critical tasks and errors associated with intercostal chest drain insertion, in order to develop enhanced procedural guidelines for task performance and training. METHODS: Expert emergency medicine physicians participated in a three-phased study. First, hierarchical task analyses was used to identify tasks, sub-tasks, and the sequence of tasks. Second, systematic human error reduction and prediction approach was used to identify and classify the errors associated with each sub-task culminating in a probability, criticality, and detectability rating for each error. Third, failure modes, effects and criticality analysis technique was used to convert probability and criticality estimates to occurrence and severity scores. Criticality index score, a measure of the propensity for the error to cause harm or procedural failure for each error, was calculated and the top 20 errors most likely to cause harm were ranked. RESULTS: Thirteen tasks and 61 sub-tasks were identified and yielded 86 potential errors. Error classification included errors of action, checking, and selection. The error with the highest criticality score was 'identifying a point of entry lower than the fifth intercostal space'. The top four ranked errors all relate to the identification and correct marking of the location site for the intercostal drain within the safe triangle. CONCLUSIONS: Tasks and sub-tasks associated with intercostal chest drain insertion was described and evaluated for criticality. The most critical task was the correct identification of a safe insertion point. Applications include development of procedural guidelines with tasks vulnerable to error highlighted and training interventions that promotes safe task performance.

A computational mechanistic study on the formation of aryl sulfonyl fluorides via Bi(III) redox-neutral catalysis and further rational design.

Sulfonyl fluorides hold significant importance as highly valued intermediates in chemical biology due to their optimal balance of biocompatibility with both aqueous stability and protein reactivity. The Cornella group introduced a one-pot strategy for synthesizing aryl sulfonyl fluorides via Bi(III) redox-neutral catalysis, which facilitates the transmetallation and direct insertion of SO2 into the BiC(sp2) bond giving the aryl sulfonyl fluorides. We report herein a comprehensive computational investigation of the redox-neutral Bi(III) catalytic mechanism, disclose the critical role of the Bi(III) catalyst and base (i.e., K3PO4), and uncover the origin of SO2 insertion into the Bi(III)C(sp2) bond. The entire catalysis can be characterized via three stages: (i) transmetallation generating the Bi(III)-phenyl intermediate IM3 facilitated by K3PO4. (ii) SO2 insertion into IM3 leading to the formation of Bi(III)-OSOAr intermediate IM5. (iii) IM5 undergoes S(IV)-oxidation yielding the aryl sulfonyl fluoride product 4 and liberating the Bi(III) catalyst for the next catalytic cycle. Each stage is kinetically and thermodynamically feasible. Moreover, we explored other some small molecules (NO2, CO2, H2O, N2O, etc.) insertion reactions mediated by the Bi(III)-complex, and found that NO2 insertions could be easily achieved due to the low insertion barriers (i.e., 17.5 kcal/mol). Based on the detailed mechanistic study, we further rationally designed additional Bi(III) and Sb(III) catalysts, and found that some of which exhibit promising potential for experimental realization due to their low barriers (<16.4 kcal/mol). In this regard, our study contributes significantly to enhancing current Bi(III)-catalytic systems and paving the way for novel Bi(III)-catalyzed aryl sulfonyl fluoride formation reactions.

Generation of Tailored Multi-Material Microstructures Through One-Step Direct Laser Writing.

Direct laser writing has gained remarkable popularity by offering architectural control of 3D objects at submicron scales. However, it faces limitations when the fabrication of microstructures comprising multiple materials is desired. The generation processes of multi-material microstructures are often very complex, requiring meticulous alignment, as well as a series of step-and-repeat writing and development of the materials. Here, a novel material system based on multilayers of chemically tailored polymers containing anthraquinone crosslinker units is demonstrated. Upon two-photon excitation, the crosslinkers only require nearby aliphatic C,H units as reaction partners to form a crosslinked network. The desired structure can be written into a solid multi-layered material system, wherein the properties of each material can be designed at the molecular level. In this way, C,H insertion crosslinking (CHic) of the polymers within each layer, along with simultaneous reaction at their interfaces, is performed, leading to the one-step fabrication of multi-material microstructures. A multi-material 3D scaffold with a sixfold symmetry is produced to precisely control the adhesion of cells both concerning surface chemistry and topology. The demonstrated material system shows great promise for the fabrication of 3D microstructures with high precision, intricate geometries and customized functionalities.

Direct muscle neurotization: Previous advancements in animal models.

Peripheral nerve repair is daily activity for several microsurgeons. Numerous nerve repair techniques are applied, including neurorrhaphy, nerve grafting and nerve transfer, depending on the nature and extent of the injury. However, these techniques become unfeasible when the distal nerve end is not preserved during the peripheral nerve injury or a segment of the muscle is transferred without the nerve supplying it. However, direct muscle neurotization (DMN) achieves muscle reinnervation by suturing the nerve directly into the muscle tissue, without requiring a distal nerve end for coaptation. Despite promising results in the literature, DMN is not widely adopted in clinical practice. Animal models may help in advancing novel therapeutic approaches, due to their anatomic and physiologic similarities to humans. This review highlights the current scientific understanding and recent advancements in DMN as well as the animal models and target muscle that have been used in the past to investigate the basic principles behind this surgical technique. The presented information should aid in establishing the clinical importance of DMN in peripheral nerve injury.

Identification and functional analysis of recent IS transposition events in rhizobia.

Rhizobia are alpha- and beta- Proteobacteria that, through the establishment of symbiotic interactions with leguminous plants, are able to fix atmospheric nitrogen as ammonium. The successful establishment of a symbiotic interaction is highly dependent on the availability of nitrogen sources in the soil, and on the specific rhizobia strain. Insertion sequences (ISs) are simple transposable genetic elements that can move to different locations within the host genome and are known to play an important evolutionary role, contributing to genome plasticity by acting as recombination hot-spots, and disrupting coding and regulatory sequences. Disruption of coding sequences may have occurred either in a common ancestor of the species or more recently. By means of ISComapare, we identified Differentially Located ISs (DLISs) in nearly related rhizobial strains of the genera Bradyrhizobium, Mesorhizobium, Rhizobium and Sinorhizobium. Our results revealed that recent IS transposition could have a role in adaptation by enabling the activation and inactivation of genes that could dynamically affect the competition and survival of rhizobia in the rhizosphere.

A Study of Factors Predicting Difficulties in Transesophageal Echocardiography (TEE) Probe Insertion in Adult Patients Undergoing Cardiac Surgery.

Background and objective While transesophageal echocardiography (TEE) is crucial in cardiac surgery, the probe insertion can be challenging. This observational study aimed to identify predictive factors associated with difficult TEE probe insertion in adult cardiac surgery patients. Methods A total of 119 adult patients undergoing cardiac surgery were included in the study. Demographic variables (age, gender, and BMI) and airway factors (modified Mallampati classification, modified Cormack-Lehane grading, and thyromental distance) were analyzed. The difficulty of TEE probe insertion was categorized into three grades, and various maneuvers were assessed for difficult insertions. Results Of note, 30.3% of insertions were difficult. Male gender (OR: 1.8), BMI ≥30 kg/m2 (OR: 2.5), Mallampati class III-IV (OR: 3.2), Cormack-Lehane grade IIb-IV (OR: 2.7), and thyromental distance <6.5 cm (OR: 1.9) were significantly associated with difficult insertion. Jaw thrust was the most effective maneuver (58.3%) for difficult cases. Conclusions Based on our findings, several demographic and airway factors predict difficulties in TEE probe insertion. Understanding these factors can help clinicians anticipate challenges and prepare appropriate strategies, potentially reducing complications associated with probe insertion.

Use of Synchrotron Radiation Circular Dichroism to Analyze the Interaction and Insertion of Proteins into Bacterial Outer Membrane Vesicles.

Circular dichroism (CD) is a spectroscopic technique commonly used for the analysis of proteins. Particularly, it allows the determination of protein secondary structure content in various media, including the membrane environment. In this chapter, we present how CD applications can be used to analyze the interaction of proteins with bacterial outer membrane vesicles (OMVs). Most CD studies characterizing the structure of proteins inserted into membranes rely on artificial lipid bilayers, mimicking natural membranes. Nevertheless, these artificial models lack the important features of the true membrane, especially for the outer membrane of Gram-negative bacteria. These features include lipid diversity, glycosylation, and asymmetry. Here, we show how to analyze the interactions of proteins, either integral or peripheral, with OMVs in solution and with supported membranes of OMVs, using conventional CD and orientated circular dichroism (OCD). We explain how to decipher the spectroscopic signals to obtain information on the molecular structure of the protein upon its interaction with an OMV and through its potential insertion into an OMV membrane.

Malposition of Percutaneous Endoscopic Gastrostomy (PEG) Tube Through the Transverse Colon: A Novel Approach to Conservative Management.

Percutaneous endoscopic gastrostomy (PEG) is a common technique for enteral nutrition support. Complications range from skin injuries and leakage to more severe intraabdominal pathologies. This case report describes a patient with invasive right lateral pharyngeal wall squamous cell carcinoma who developed a gastrocolocutaneous fistula following PEG tube malpositioning in the transverse colon performed at an outside institution. Based on the patient's comorbidities and the associated high-risk nature of the surgery, a transverse colectomy and partial gastrectomy to resect the malpositioned tube followed by a new PEG tube was deemed invasive and would likely have a poor clinical outcome. Instead, the surgeon performed a laparoscopic-assisted PEG tube insertion in another portion of the stomach. The fistulous tract of the original PEG tube was completely sealed and fell out one week following surgery. The patient tolerated feeds through the new PEG tube site. Gastrocolocutaneous fistulas are rare complications of PEG tube insertion with a poorly understood pathophysiology. Here, we analyze the root cause of this condition, steps to mitigate it, and a proposed novel surgical approach for its conservative management.

Comparing Male and Female Resident Physicians in Central Venous Catheter Insertion Self-confidence and Competency: A Retrospective Cohort Study.

BACKGROUND: Female physicians often report lower self-confidence in their procedural and clinical competency compared to male physicians. There is limited data regarding self-reported confidence of female versus male trainees and any relation to objective competency in central venous catheter insertion. OBJECTIVE: To analyze differences between male and female trainees in self-confidence and skill-based outcomes in placing central venous catheters. DESIGN: Using data from a central venous catheter simulation training program at a large tertiary medical center, we performed linear regressions to analyze confidence difference pre- and post-training, number of restarts, and number of cannulation attempts while controlling for baseline demographic characteristics of the sample. PARTICIPANTS: PGY-1 physician residents in all residency specialties who insert central venous catheters in the clinical setting at a tertiary academic center with a sample size of 281 residents. MAIN MEASURES: Confidence difference pre- and post-training measured on a Likert scale 1-5, number of restarts (novel global assessment variable), and number of cannulation attempts during the competency evaluation. KEY RESULTS: Female trainees had both lower pre-program confidence (1.35 versus 1.74 out of 5, p < 0.001) and lower post-program confidence (3.77 versus 4.12 out of 5, p = 0.0021) as compared to male trainees. There was no statistically significant difference in number of restarts (95% CI - 0.073 to 0.368, p = 0.185) or cannulation attempts (95% CI - 0.039 to 0.342, p = 0.117) between sexes in linear regressions controlled for age, specialty designation, prior central venous catheter training, prior ultrasound guided vessel cannulation training, and pre-training confidence level. CONCLUSIONS: Female trainees rated their confidence significantly lower than their male counterparts both before and after the training program, despite no significant difference in skill-based outcomes. We discuss potential implications for trainees acquiring procedural skills during residency and for physician educators as they design training programs and delegate procedural opportunities.

Finite-element modelling of interactions of needle with tympanic membrane and middle ear.

The tympanic membrane (TM) is one of the most common routes to access the middle ear and inner ear for the treatment of hearing and balance pathologies. Since the TM is a soft thin biological tissue with small dimensions, using needles seems to be among the most practical interventional approaches. In this study, we proposed a finite-element (FE) analysis of needle-TM interactions that combines a 3D model of the TM and other main middle-ear structures in gerbil, and a 2D model of needle insertion into the TM based on the cohesive zone method (CZM). The TM was modelled using a 1st-order Ogden hyperelastic material and its properties were obtained by fitting to the experimental force-displacement plots of large deformation in the TM under needle indentation. The cohesive parameters were also acquired by calibrating the puncture force against the experimental data of needle insertion into the TM. These FE models were then used to obtain the deformation behaviour of the TM and other middle-ear structures due to the insertion force applied at different locations on the TM. Moreover, we investigated the effect of the TM thickness, the geometry of the needle (i.e., diameter and tip angle), and needle material on the insertion of needles into the TM. We also studied the penetration success of deformable needles.

Association of congenital uterine anomaly with abnormal placental cord insertion and adverse pregnancy complications: a retrospective cohort study.

OBJECTIVE: Congenital uterine anomalies during pregnancy increase the risk of pregnancy complications such as miscarriage, preterm delivery, fetal malpresentation, cesarean delivery, and fetal growth restriction. However, few studies have examined uterine anomalies in relation to perinatal complications other than those mentioned above. We investigated the association between pregnancies complicated by congenital uterine anomalies and various perinatal outcomes at our institution. METHODS: This retrospective cohort study was conducted from January 2009 to May 2021. We included cases of uterine anomalies, such as septate, bicornuate, unicornuate, and didelphic uterus. First, the perinatal complications and neonatal outcomes were compared between pregnancies complicated by uterine anomalies and those with normal uteri. Second, we conducted an analysis based on the type of uterine anomalies classified into two groups: the minor anomaly group consisted of anomalies limited to the uterine cavity, such as the septate uterus, whereas the major anomaly group included anomalies affecting the uterine shape, such as bicornuate, unicornuate, and didelphic uterus. We compared the incidence of perinatal complications among the major anomaly, minor anomaly, and normal uterus groups. RESULTS: During the study period, 45 pregnancies were complicated with uterine anomalies. The minor anomaly group included 11 patients and the major anomaly group included 34 patients. The incidence of fetal malpresentation was significantly higher in the uterine anomaly group than in the normal uterus group (18% vs. 3.7%, p = .04). Furthermore, the frequency of abnormal placental cord insertion was significantly higher in the uterine anomaly group (16% vs. 3.7%, p = .01). Examination based on the type of uterine anomaly revealed significant differences in cervical incompetence, malpresentation, cesarean section, and abnormal placental cord insertion. Cervical incompetence was more likely in patients with minor anomalies. In contrast, fetal malpresentation, cesarean section, and abnormal placental cord insertion were more likely in the major anomaly group. CONCLUSIONS: In addition to the findings reported in previous studies, abnormal placental cord insertion was more frequent in pregnancies complicated by uterine anomalies.

Association between angiotensin-converting enzyme gene insertion/deletion polymorphism and cognition impairment in patients with schizophrenia.

RATIONALE: Several lines of evidence indicate that an insertion/deletion (I/D) polymorphism in the angiotensin-converting enzyme gene (ACE) gene may be involved in the pathogenesis of schizophrenia and cognitive impairment. However, the relationship between ACE I/D polymorphism and cognitive impairment in patients with schizophrenia remains unclear. OBJECTIVES: The aim of this study was to examine whether ACE gene I/D polymorphism contributed to cognitive impairment in Chinese patients with schizophrenia, and whether the association between clinical symptoms and cognitive impairment depended on different ACE genotypes. METHODS: The ACE I/D polymorphism was genotyped in 928 schizophrenia patients and 325 healthy controls using a case-control design. The severity of psychopathological symptoms was assessed using the Positive and Negative Syndrome Scale (PANSS). Cognitive functioning was assessed by the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). RESULTS: There were significant differences in genotype and allele frequencies of the ACE I/D polymorphism between patients and healthy controls (both P < 0.01). After controlling for demographic characteristics, patients who are homozygous carriers of D and I performed worse on the RBANS attention index than heterozygous carriers (P = 0.009). In addition, attention index score was negatively correlated with PANSS negative symptom score in patients of all genotypes (all P < 0.05), and positively correlated with positive symptom score only in the I/I genotype (P = 0.005). CONCLUSIONS: These findings suggest that ACE I/D gene variants play a role in susceptibility to schizophrenia, specific cognitive impairment and the association between clinical symptoms and cognitive impairment in schizophrenia patients.

A method for predicting needle insertion deflection in soft tissue based on cutting force identification.

The deflection modeling during the insertion of bevel-tipped flexible needles into soft tissues is crucial for robot-assisted flexible needle insertion into specific target locations within the human body during percutaneous biopsy surgery. This paper proposes a mechanical model based on cutting force identification to predict the deflection of flexible needles in soft tissues. Unlike other models, this method does not require measuring Young's modulus (E) and Poisson's ratio (ν) of tissues, which require complex hardware to obtain. In the model, the needle puncture process is discretized into a series of uniform-depth puncture steps. The needle is simplified as a cantilever beam supported by a series of virtual springs, and the influence of tissue stiffness on needle deformation is represented by the spring stiffness coefficient of the virtual spring. By theoretical modeling and experimental parameter identification of cutting force, the spring stiffness coefficients are obtained, thereby modeling the deflection of the needle. To verify the accuracy of the proposed model, the predicted model results were compared with the deflection of the puncture experiment in polyvinyl alcohol (PVA) gel samples, and the average maximum error range predicted by the model was between 0.606 ± 0.167 mm and 1.005 ± 0.174 mm, which showed that the model can successfully predict the deflection of the needle. This work will contribute to the design of automatic control strategies for needles.

Effects of exposure length, cortical and trabecular bone contact areas on primary stability of infrazygomatic crest mini-screws at different insertion angles.

BACKGROUND: The infrazygomatic crest mini-screw has been widely used, but the biomechanical performance of mini-screws at different insertion angles is still uncertain. The aim of this study was to analyse the primary stability of infrazygomatic crest mini-screws at different angles and to explore the effects of the exposure length (EL), screw-cortical bone contact area (SCA), and screw-trabecular bone contact area (STA) on this primary stability. METHODS: Ninety synthetic bones were assigned to nine groups to insert mini-screws at the cross-combined angles in the occlusogingival and mesiodistal directions. SCA, STA, EL, and lateral pull-out strength (LPS) were measured, and their relationships were analysed. Twelve mini-screws were then inserted at the optimal and poor angulations into the maxillae from six fresh cadaver heads, and the same biomechanical metrics were measured for validation. RESULTS: In the synthetic-bone test, the LPS, SCA, STA, and EL had significant correlations with the angle in the occlusogingival direction (rLPS = 0.886, rSCA = -0.946, rSTA = 0.911, and rEL= -0.731; all P < 0.001). In the cadaver-validation test, significant differences were noted in the LPS (P = 0.011), SCA (P = 0.020), STA (P = 0.004), and EL (P = 0.001) between the poor and optimal angulations in the occlusogingival direction. The STA had positive correlations with LPS (rs = 0.245 [synthetic-bone test] and r = 0.720 [cadaver-validation test]; both P < 0.05). CONCLUSIONS: The primary stability of the infrazygomatic crest mini-screw was correlated with occlusogingival angulations. The STA significantly affected the primary stability of the infrazygomatic crest mini-screw, but the SCA and EL did not.