Low Volume Research Articles

Tubes in complex hyperbolic manifolds

We prove a tubular neighborhood theorem for an embedded complex geodesic in a complex hyperbolic 2-manifold where the width of the tube depends only on the Euler characteristic χ \chi of the embedded complex geodesic. We give an explicit estimate for this width. We supply two applications of the tubular neighborhood theorem. The first is a lower volume bound for such manifolds. The second is an upper bound on the first eigenvalue of the Laplacian in terms of the geometry of the manifold. Finally, we prove a geometric combination theorem for two C \mathbb {C} -Fuchsian subgroups of PU ⁡ ( 2 , 1 ) \operatorname {PU}(2,1) . Using this combination theorem, we show that the optimal width size of a tube about an embedded complex geodesic is asymptotically bounded between 1 | χ | \frac {1}{|\chi |} and 1 | χ | \frac {1}{\sqrt {|\chi |}} .

High gain Bi-directional KY converter for low power EV applications

In electric vehicles (EVs), the type of electric motor and converter technology have a significant impact on regulating the operational characteristics of the vehicle. Therefore, in this work, the modified bi-directional KY converter (BKYC) is proposed for EV applications. The main contributions of the proposed converter are high step-up/step-down conversion gain, bi-directional power flow, simplified control structure, continuous current, common ground, low volume, and high efficiency. An inductor on either side of the converter ensures continuous current flow and passive components are arranged to operate in series to offer high step-up/step-down conversion. The charging and discharging operations, steady-state analysis, and design process of the proposed converter are discussed in detail and compared with similar bi-directional converter topologies. Further, the efficiency analysis of the proposed converter is presented and found that the efficacy of 95.51 % in charging operation and 96.52 % in discharging operation of operation. The simulations are carried out using MATLAB/Simulink environment. Further, a prototype of a modified bi-directional KY converter is implemented with a TMS320F28335 processor and validated with theoretical and simulation counterparts.

Respiratory Dysfunction and Abnormal Hypoxic Ventilatory Response in Mild to Moderate Parkinson's Disease.

Respiratory dysfunction is an important contributor to morbidity and mortality in advanced Parkinson's disease (PD), but it is unclear what parameters are sensitive to diagnose and monitor respiratory dysfunction across disease phases. We aimed to characterize respiratory dysfunction in mild to moderate PD. In 20 individuals without cardiopulmonary comorbidity, pulmonary and inspiratory muscle function testing were performed ON-medication. Subsequently, the acute ventilatory response to hypoxia (HVR) was assessed by gradually decreasing FIO2 from 0.209 (room air) to 0.127, which was compared to eight age- and sex-matched healthy controls under arterial blood gas monitoring. Lastly, on different days, the same 20 individuals with PD underwent six blinded exposures to 45-min normobaric hypoxia at FiO2 0.163 and 0.127 or placebo OFF-medication to assess breathing responses. At rest, individuals with greatest PD severity had a lower tidal volume (pairwise comparisons: 0.59 vs. 0.74, P = 0.038-0.050) and tended to have a higher breathing frequency (17.7 vs. 14.4, P = 0.076), despite normal pulmonary function. A 45-min exposure to hypoxia induced a significantly lower acute HVR in individuals with PD compared to controls (-0.0489 vs. 0.133 L.min/%, P = 0.0038). Acute HVR was reduced regardless of disease severity. Subacute HVR in individuals with milder disease tended to be higher compared to those with more advanced disease (P = 0.079). Respiratory dysfunction is present in individuals with PD, including those with relatively mild disease severity, and is characterized by altered breathing patterns at rest, as well as a lower HVR, despite normal pulmonary and inspiratory muscle function testing.

Deformation characteristics of Ti-Ni-Fe based multiphase intermetallic: Experiments and atomistic simulation

This study deals with the development of Ti-Ni-Fe based multi-phase intermetallic having high strength with enhanced ductility and elucidation of their deformation characteristics. The intermetallic exhibited a compressive strain and strength of ⁓ 11 % and ⁓ 2.1± 0.112 GPa at room temperature (RT), respectively. MD simulation at RT showed a higher dislocation density in the DO24 phase, where most of the dislocations were found to be superpartials 13101̅0 and 1311̅00 separated by super intrinsic stacking faults (SISF), which was further corroborated with TEM analysis. It was found that despite its low volume fraction, DO24 phase governed the plastic deformation. Further, hot compression of Ti45Ni50Fe5 exhibited yield strength anomaly (YSA), where yield strength decreased from room temperature to 373 K followed by an increase at 473 K and 573 K. MD simulation of hot compression showed lower dislocation density (⁓300–551×10−6Å−2) for B2 matrix at all temperatures, indicating strength is predominantly governed by it. The dislocation density of B2 matrix was found to increase with temperature up to 373 K followed by a decrease at 473 K and 573 K. This difference in dislocation density has been attributed to the cross-slip of 121̅11 screw partials from {110} plane to {211} plane, resulting in the formation of dislocation lock that led to YSA behavior.

The role of cydB gene in the biofilm formation by Campylobacter jejuni

Campylobacter jejuni is a major cause of food- and water-borne bacterial infections in humans. A key factor helping bacteria to survive adverse environmental conditions is biofilm formation ability. Nonetheless, the molecular basis underlying biofilm formation by C. jejuni remains poorly understood. Around thirty genes involved in the regulation and dynamics of C. jejuni biofilm formation have been described so far. We applied random transposon mutagenesis to identify new biofilm-associated genes in C. jejuni strain 81–176. Of 1350 mutants, twenty-four had a decreased ability to produce biofilm compared to the wild-type strain. Some mutants contained insertions in genes previously reported to affect the biofilm formation process. The majority of identified genes encoded hypothetical proteins. In the library of EZ-Tn5 insertion mutants, we found the cydB gene associated with respiration that was not previously linked with biofilm formation in Campylobacter. To study the involvement of the cydB gene in biofilm formation, we constructed a non-marked deletion cydB mutant together with a complemented mutant. We found that the cydB deletion-mutant formed a weaker biofilm of loosely organized structure and lower volume than the parent strain. In the present study, we demonstrated the role of the cydB gene in biofilm formation by C. jejuni.

Closed-incision negative pressure wound therapy (NPWT) in elderly patients following sacral pressure sore reconstruction

BackgroundPressure sores significantly affect elderly patients, with the sacrum being especially vulnerable, often due to its proximity to the anus and potential for fecal contamination. Despite preventive measures such as frequent repositioning and specialized cushions, some sores still necessitate surgical intervention. Postoperative care focuses on monitoring, hygiene, and pressure alleviation. This study assessed the efficacy of Closed-Incision Negative Pressure Wound Therapy (CI-NPWT) for postoperative wound management in patients with sacral pressure sores treated with local flaps.MethodsA retrospective analysis was performed on sacral sore patients who underwent reconstructive surgery from March 2019 through April 2023. Surgical procedures involved debridement and wound coverage using gluteal artery perforator-based fasciocutaneous flaps, followed by postoperative monitoring. Patients were grouped into conventional monitoring or NPWT management, with the latter utilizing the INFOV.A.C. The therapy unit was calibrated to 125 mmHg. Data on patient demographics, flap metrics, fluid drainage amounts, and six-month postoperative outcomes were collected, and then analyzed with SPSS Statistics.ResultsIn this study of 52 patients with sacral pressure sores, the NPWT group (n = 25) showed significantly fewer flap complications and a lower drainage volume on the seventh postoperative day (mean 17.2 cc) compared to the conventional dressing group (mean 27.8 cc, P < 0.05). No postoperative complications were observed in the NPWT group, whereas the conventional group (n = 27) experienced one infection and three cases of dehiscence. Both groups achieved a 100% flap survival rate.ConclusionClosed-incision negative pressure wound therapy (CI-NPWT) shows promise in reducing wound dehiscence and infection rates in elderly patients undergoing sacral pressure sore reconstruction with local flaps. However, further research with larger, randomized studies is needed to confirm its effectiveness as an alternative to conventional postoperative care.Trial registration.The study was retrospectively registered by the Institutional Review Board of Seoul Metropolitan Government-Seoul National University Boramae Medical Center (No. 20–2023–25, Date: Mar. 24 2023).

In-hospital bioimpedance-derived total body water predicts short-term cardiovascular mortality and re-hospitalizations in acute decompensated heart failure patients.

Hospital re-admissions in heart failure (HF) patients are mostly caused by an acute exacerbation of their chronic congestion. Bioimpedance analysis (BIA) has emerged as a promising non-invasive method to assess the volume status in HF. However, its correlation with clinically assessed volume status and its prognostic value in the acute intra-hospital setting remains uncertain. In this single-center observational study, patients (n = 49) admitted to the cardiology ward for acute decompensated HF (ADHF) underwent a daily BIA-derived volume status assessment. Median hospital stay was 7 (4-10) days. Twenty patients (40%) reached the composite endpoint of cardiovascular mortality or re-hospitalization for HF over 6months. Patients at discharge displayed improved NYHA class, lower body weight, plasma and blood volume, as well as lower NT-proBNP levels compared to the admission. Compared to patients with total body water (TBW) less than or equal to that predicted by body weight, those with higher relative TBW levels had elevated NT-proBNP and E/e´ (both p < 0.05) at discharge. In the Cox multivariate regression analysis, the BIA-derived delta TBW between admission and discharge showed a 23% risk reduction for each unit increase (HR = 0.776; CI 0.67-0.89; p = 0.0006). In line with this finding, TBW at admission had the highest prediction importance of the combined endpoint for a subgroup of high-risk HF patients (n = 35) in a neural network analysis. In ADHF patients, BIA-derived TBW is associated with the increased risk of HF hospitalization or cardiovascular death over 6months. The role of BIA for prognostic stratification merits further investigation.

Examination of dental utilization of newly resettled adult refugees in Washington state enrolled in dental medicaid program.

To assess dental utilization of resettled adult refugees in Washington (WA) state and the demographic factors associated with dental utilization. Data were collected between January 1, 2015, and December 31, 2015 for newly arrived adult refugees (>21 years) enrolled in Washington State dental Medicaid program. Three state agencies provided enrollment and claims data that included demographic information as well as number and types of dental claims, and time to first dental claim for the newly resettled adult refugee population. A total of 1294 adult refugees resettled in WA State in 2015. Approximately, 67% were aged 21-39 years and 32.4% White race and 93.9% without any disability. Over half (57%) of adult refugees had at least one dental claim within 12 months, and the median time to first dental utilization was 4.1 months [IQR:2.4-6.8]. Black refugees had a 74% greater chance of a first dental claim within 12 months of resettlement compared to White refugees (p < .001), and people from countries with high volume of refugees also had a 31% greater chance than those from countries with low volume of refugees (p = .005). Over half of all the adult refugees resettled in WA utilized dental services within 12 months of arrival. Understanding the mosaic of demographic backgrounds of newly resettled refugees in any given state will improve early utilization of dental care needs and therefore improve their oral health.

Determination of effects of climate change on hydropower generation at Kamburu dam-Kenya.

This study aimed to determine the effects of climate change on hydropower generation at Kamburu Dam, Kenya. Kamburu power plant has been experiencing low volumes of water with the shortage of rainfall from its catchment area. This study primarily utilised rainfall and temperature data, as well as field survey data collected through questionnaires. Primary data was collected using questionnaires, photography, checklists, and observation guides. Secondary data sources included Kengen and the meteorological department's annual reports. The study used simple stratified sampling. The four villages of the Kivaa sub-location were sampled into 20 households, making a total of 80 households; Kengen and meteorological stations sampled every 10 respondents to make a total of 100 respondents. Collected data from the questionnaires were coded and analysed using SPSS 29. The results of this research showed that the area experiences increasing temperatures of 0.044? every year and decreasing rainfall of 0.5897mm every year. The research forecasted a decadal increase in temperature of 0.44? and a decadal decrease in rainfall of 5.897mm. The research also showed a decrease in hydropower of 18,790MWH every year, translating to a decadal decrease of 187,790MWH. The research concluded that climate change has greatly affected hydropower production at the Kamburu Dam power plant. The research recommends afforestation and re-afforestation activities, putting rules and regulations of watershed management, upgrading the Kamburu dam infrastructure to fit climate-resilient, expanding the capacity of the dam, and energy storage, among others.

Time to Next Treatment Following Sub-Ablative Progression Directed Radiation Therapy for Oligoprogressive Non-Small-Cell Lung Cancer

We aimed to evaluate whether progression-directed radiation therapy (PDRT) can prolong the initiation of a subsequent systemic therapy regimen in a cohort of patients with oligoprogressive NSCLC. A retrospective analysis was conducted on NSCLC patients who underwent PDRT for extracranial oligoprogressive NSCLC, defined as limited (up to five) progressing lesions following initial complete, partial, or stable response to systemic therapy according to REC1ST 1.1 and/or PERCIST 1.0 criteria. Cox proportional hazard regressions were performed to identify factors influencing time to next treatment (TTNT), which was considered the primary endpoint. Forty patients were analyzed. First, second, and ≥3 lines of systemic therapy were administered in 22 (58.2%), 14 (27.2%), and 4 (14.6%) cases, respectively. The median total dose was 36 Gy (range: 12–60) in five fractions (1–10), with a median biological effective dose for tumor control (BED10) of 52 Gy (26.4–151.2). After a median follow-up of 11 months (2–50), PDRT delayed further systemic therapy in 32 (80.0%) treatments. Median TTNT was not reached at 8 months (1–47) with a one-year Kaplan–Meier estimate of 81.4% (95% CI: 75.0% to 87.8%). No &gt;grade 3 adverse event was observed. On multivariate analysis, patients with ≥3 lines of systemic therapy and/or with larger CTV volumes did not benefit from PDRT. Despite the use of sub-ablative doses, our findings show that PDRT represents an effective, safe, and viable option for oligoprogressive NSCLC. Patients irradiated early during their systemic treatment course, with a low volume of disease and nonmetastatic oligoprogression, could derive substantial benefits from PDRT.

Low-Volume Surgeons Operating at High-Volume Hospitals Have Low Rates of Periprosthetic Joint Infection after Hip and Knee Arthroplasty

IntroductionThe relationship between surgeon and hospital case volumes and postoperative risk following total hip and total knee arthroplasty (THA and TKA) has been described independently. This study aimed to assess the risk of periprosthetic joint infection (PJI) following primary TKA and THA to determine if lower volume surgeons operating at higher volume centers would have lower rates of complications compared to lower volume surgeons operating at lower volume hospitals. MethodsA healthcare database was used to retrospectively identify all primary, and elective total joint arthroplasties (TJAs) from October 2015 to December 2021. Using restricted cubic splines, high-volume hospitals were defined using Markov chain Monte Carlo simulation, which identified a volume beyond which PJI rates no longer decreased significantly with increasing hospital volume. A similar methodology was used to identify low-volume surgeons operating in high- and low-volume hospitals. There were 605,254 patients who underwent TJA (total hip arthroplasty [THA]: 37.71%; total knee arthroplasty [TKA]: 62.29%) by low-volume surgeons (< 57 THAs and < 68 TKAs) identified and divided into high-volume and low-volume hospital cohorts. High-volume hospitals were defined as > 508 THA and > 812 TKAs per year, and low-volume hospitals were defined as < 145 THAs and < 243 TKAs per year. Multivariable models accounting for potential confounding covariates were created to determine the odds of PJI between cohorts. ResultsAfter taking confounding variables into account, low-volume surgeons at high-volume hospitals had lower rates of PJI relative to their counterparts at low-volume hospitals (THA 0.67 versus 0.80%, aOR [adjusted odds ratio] = 0.69 [95% confidence interval (CI) = 0.54 to 0.88], P = 0.002; TKA 0.51 versus 0.69%, aOR = 0.73, [95%-CI = 0.61 to 0.87], P = 0.007). ConclusionIncreasing institutional case volume may mitigate the increased risk of PJI associated with low annual surgeon case volume.

Reduction of masseter muscle prominence after treatment with onabotulinumtoxinA: primary results from a randomized phase 2 study

OnabotulinumtoxinA is used to treat masseter muscle prominence (MMP). To assess the safety and efficacy of onabotulinumtoxinA for MMP in a randomized study. This 12-month, multicenter, double-blind, placebo-controlled, phase 2 study randomized adults (18-50 years of age) with marked/very marked bilateral MMP (≥4 on the Masseter Muscle Prominence Scale [MMPS]) to onabotulinumtoxinA (24, 48, 72, or 96 U) or placebo; retreatment occurred at day 180 if MMPS ≥4. Lower facial volume at day 90 was measured using Vectra 3-dimensional photography. Safety assessments included computed tomography and dental exams. Evaluations occurred monthly through day 360. Among 187 randomized subjects, significant lower facial volume reductions and percentage of responders (MMPS grade ≤3) were greater with onabotulinumtoxinA versus placebo at day 90 (P < .001 and ≤ .008, respectively). Similar efficacy was observed with retreatment. No dose-related safety trends or clinically relevant changes in the mandible or teeth occurred. Localized impact on smile was reported with 96 U onabotulinumtoxinA (n=4). Limited sample size per individual treatment group. OnabotulinumtoxinA administered in 1 or 2 treatments over 1 year was associated with significant reductions in masseter muscle volume and MMP severity, with an acceptable safety profile.

Nationwide analysis of one-year mortality following pancreatectomy in 17,183 patients with pancreatic cancer

BackgroundThe use of 1-year mortality following pancreatectomy for PDAC as a measure of surgical quality has not been evaluated. We aim to i) assess the 1-year mortality rate following pancreatectomy for PDAC, and ii) identify patient and hospital characteristics associated with 1-year mortality. MethodsData was extracted retrospectively from the French national medico-administrative database. The study included patients who underwent pancreatectomy for PDAC between January 2012 and December 2019. The primary outcome was 1-year postoperative mortality. Hospitals were classified based on volume (high (≥26 resections/year) and low volume (<26)). ResultsOverall, 17,183 patients who underwent pancreatectomy for PDAC were included. The overall 90-day and 1-year mortalities were 6.5 % and 21.5 %, respectively. 1-year mortality varied significantly between low and high-volume hospitals (23.6 % vs. 18.6 %, respectively, p < 0.001). Older age, Charlson Comorbidity Index (CCI), readmission, major complications were predictive factors for 1-year mortality. Pancreatectomy in low volume hospitals increased the risk of 1-year mortality by 1.23-fold (OR = 1.23, 95 % CI [1.15–1.32], p < 0.001). DiscussionThe overall 1-year mortality after pancreatectomy for PDAC was 21.5 %, and was higher in patients of older age, with higher comorbidities, who experienced major complications, and who did not receive adjuvant therapy. Management in high-volume centers decreased mortality rates, regardless of the patient’s condition.

Dose-response effects of 8-week resistance training on body composition and muscular performance in untrained young women: A quasi-experimental design.

The purpose of this study was to investigate the effects of 8-week resistance training with different training volumes on body composition, maximum strength, peak power, and muscle thickness in non-training women. This was a 3-arm, prospectively designed, randomized controlled trial. A total of 45 adult women aged 20.7 ± 1 years, the mean heights of the participants were 166 ± 0.07 cm, body weight was measured as 54.5 ± 8.8 kg, and body mass index was 19.9 ± 2.1 kg/m2. They were randomized to low-volume training resistance training (LVT; n = 15, 3 sessions of 12 exercises per week), moderate-volume training resistance training (MVT; n = 15; 4 sessions of 12 exercises per week), and high-volume resistance training (HVT; n = 15; 5 sessions of 12 exercises per week) for 8 weeks. The muscle thickness (MT) of the vastus lateralis was assessed at baseline and 8 weeks later using a portable ultrasound device. A total of 39 adult women completed the study, with 2 participants from each group lost to follow-up. All experimental groups 1RM increased (P = .001, effect size (ES) = 0.463) All groups showed improved muscle thickness (MT) (P = .001) and CMJ (P = .004). The group × time interaction is statistically significant (P = .001) suggests that the changes in muscle thickness over time differ significantly between the different training volume groups (ηp²) is 0.368. In untrained young women, resistance training improved muscle hypertrophy, maximal strength, power, and body composition in untrained young women. However, 4 sessions MVT per week were superior to LVT and HVT sessions, suggesting a nonlinear dose-response relationship favoring moderate volume over low or high volumes, at least in previously untrained young women. ClinicalTrials.gov (NCT06449300).

Case Volume Is Not Associated With Outcomes After Adrenalectomy Performed by Urologic Surgeons.

Our goal was to compare outcomes of adrenalectomy performed by low-volume and high-volume academic urologists with extensive experience in renal surgery. A single-center retrospective review identified patients undergoing adrenalectomy by urologists from 2009 to 2023. Data were gathered on demographics, tumor characteristics, surgeon volume, surgical outcomes including length of procedure, estimated blood loss, length of stay, and complications identified by the Clavien-Dindo complication classification system. Bivariable and multivariable analyses adjusting for BMI, size of mass, age, and surgical approach compared outcomes between low- and high-volume adrenalectomy surgeons. A total of 304 adrenalectomies were performed by 7 urologic surgeons during the study period. One surgeon was high volume, with an average of 15 adrenalectomies per year during the study period. The remaining 6 surgeons ranged from < 1 to 4 adrenalectomies per year on average during the study period and were considered low volume. On multivariable analysis, the rate of any complication was found to be significantly different between the groups (5.3% vs 13.5%, P = .01). However, on analysis of Clavien 3 or higher complications, the rate was not found to be different (1% vs 4%, P = .22). Procedure time (130 vs 134 minutes, P = .33), estimated blood loss (30 vs 50 mL, P = .86), positive margin rate (11% vs 7%, P = .35), and length of stay (2 days vs 2 days, P = .22) were not different when the surgery was performed by a high-volume or low-volume urologist. Surgical volume may not affect outcomes of adrenalectomy when performed by urologists experienced in retroperitoneal surgery at a high-volume, specialized center.

Hearing Function Moderates Age-Related Differences in Brain Morphometry in the HCP Aging Cohort.

There are well-established relationships between aging and neurodegenerative changes, and between aging and hearing loss. The goal of this study was to determine how structural brain aging is influenced by hearing loss. Human Connectome Project Aging data were analyzed, including T1-weighted Magnetic Resonance Imaging (MRI) and Words in noise (WIN) thresholds (n = 623). Freesurfer extracted gray and white matter volume, and cortical thickness, area, and curvature. Linear regression models targeted (1) interactions between age and WIN threshold and (2) correlations with WIN threshold adjusted for age, both corrected for false discovery rate (pFDR < 0.05). WIN threshold moderated age-related increase in volume in bilateral inferior lateral ventricles, with a higher threshold associated with increased age-related ventricle expansion. Age-related differences in the occipital cortex also increased with higher WIN thresholds. When controlling for age, high WIN threshold was correlated with reduced cortical thickness in Heschl's gyrus, calcarine sulcus, and other sensory regions, and reduced temporal lobe white matter. Older volunteers with poorer hearing and cognitive scores had the lowest volume in left parahippocampal white matter. These results suggest that better hearing is associated with reduced age-related differences in medial temporal lobe, while better hearing at any age is associated with greater cortical tissue in auditory and other sensory regions. Future longitudinal studies are needed to assess the causal nature of these relationships, but these results indicate interventions that preserve or protect hearing function may combat some neurodegenerative changes in aging.

Ultrasound-guided quadratus lumborum block with 0.5 mL of 0.2% bupivacaine/kg is a valuable perioperative analgesic adjunct for cats undergoing ovariectomy.

To assess the perioperative analgesic effects of bilateral ultrasound (US)-guided quadratus lumborum block (QLB) using low-volume (LV) or high-volume (HV) bupivacaine, compared to a control group, in cats undergoing ovariectomy. 48 healthy female cats. Cats were sedated with IM dexmedetomidine (5 µg/kg), ketamine (1 mg/kg), and methadone (0.2 mg/kg) followed by IV propofol induction and isoflurane maintenance. Cats were randomly assigned to 3 groups of 16 patients each: QLB-LV group (0.3 mL/kg/side), QLB-HV group (0.5 mL/kg/side), and control group (no QLB). Bilateral, in-plane, US-guided QLB was performed with lateral approach at the L2 transverse process with bupivacaine 0.2%. Physiological variables were recorded intraoperatively by a masked investigator. If intraoperative nociception occurred, fentanyl (1 µg/kg) was administered IV. Rescue postoperative analgesia (buprenorphine, 0.2 mg/kg) was administered in case of a Feline Grimace Scale score ≥ 4 after a 4-hour evaluation period. In the control group, heart rate (HR) was higher than the QLB-LV group during the first ovarian manipulation (P < .001) and higher than the QLB-HV group during both ovarian manipulations (P < .001 and P = .006). The need for intraoperative rescue analgesia and postoperative pain scores were significantly higher in the QLB-LV (P = .005 and P = .047) and control (P < .001 and P < .001) groups compared to the QLB-HV group. Buprenorphine was administered once in the control group. No clinical signs of bupivacaine toxicity or QLB complications were observed. Bilateral US-guided QLB-HV may effectively provide perioperative analgesia in feline patients undergoing ovariectomy.

Leveraging machine learning for preoperative prediction of supramaximal ablation in laser interstitial thermal therapy for brain tumors.

Maximizing safe resection in neuro-oncology has become paramount to improving patient survival and outcomes. Laser interstitial thermal therapy (LITT) offers similar survival benefits to traditional resection, alongside shorter hospital stays and faster recovery times. The extent of ablation (EOA) achieved using LITT is linked to patient outcomes, with greater EOA correlating with improved outcomes. However, the preoperative predictors for achieving supramaximal ablation (EOA ≥ 100%) are not well understood. By leveraging machine learning (ML) techniques, this study aimed to identify these predictors to enhance patient selection and therefore outcomes. The objective was to explore preoperative predictors for supramaximal EOA using ML in patients with glioblastoma. A retrospective study was conducted on the medical records of 254 patients undergoing LITT from 2013 to 2023 at a single tertiary center. Cohort criteria included age ≥ 18 years, diagnosis of glioblastoma, single-trajectory ablation, and a complete dataset. The study assessed preoperative clinical and radiographic factors, using EOA ≥ 100% as the endpoint. Five ML models were used: logistic regression, random forest (RF), gradient boosting, Gaussian naive Bayes, and support vector machine. Training and testing cohorts were subsequently assessed across ML models with fivefold cross-validation. Models were optimized using hyperparameter tuning. Performance was primarily quantified using the area under the curve (AUC) of the receiver operating characteristic curve. The final cohort consisted of 72 patients. Among the ML models, RF achieved the highest AUC (mean ± SD 0.94 ± 0.06). The leading models identified that lower preoperative volume, history of prior radiation therapy, history of prior craniotomy, preoperative neurological deficits, history of preoperative seizures, and distance from intracranial heat sinks were predictive of successful ablations in patients. Additionally, RF had the best mean metrics: accuracy 0.88, precision 0.87, specificity 0.87, and sensitivity 0.89. This is the first study to investigate the role of ML for optimizing ablation volumes in LITT. These ML models suggest that low preoperative volumes, previous craniotomy, previous radiation therapy, no previous neurological deficits, larger catheter-heat sink distance, and the presence of preoperative seizures are important prognostic factors for predicting successful supramaximal ablations with LITT.

Marked microcytosis and increased transferrin saturation: Think about variants in SLC11A2 (DMT1)

Congenital microcytic anemias are rare diseases associated with decreased hemoglobin synthesis and red blood cells of low corpuscular volume. DMT1/NRAMP2 is a highly conserved divalent cation transporter encoded by the SLC11A2 gene, expressed at the membrane of various cells. It ensures ferrous iron absorption from the apical membrane of enterocytes, iron recovery from urine by renal tubules, and acidified endosome uptake after transferrin internalization. Pathogenic DMT1 variants have been described in 10 individuals to date, associated with recessive hypochromic anemia and iron overload. Herein, we report a new variant of SLC11A2 (c.469A>G, p.Ile157Val) compound with known p.Arg416Cys associated with a frankly microcytic anemia and increased transferrin saturation. The clinical picture observed in the patient was exceptionally mild, extending the field of the DMT1 phenotypes to borderline anemias.

Effect of days of age at first blood transfusion on intraventricular hemorrhage in very low and extremely low birth weight infants

ABSTRACT Background Preterm infants are a group cohort of transfusion recipients due to their low blood volume and underdeveloped hematopoietic system. The objective of this study was to probe the effect of days of age at first blood transfusion on intraventricular hemorrhage (IVH) in very low and extremely low birth weight VLBW and ELBW infants. Research design and methods Data of 150 VLBW and ELBW infants received blood transfusion were reviewed. IVH and non-IVH groups were established. General data on infants and their mothers and data related to blood transfusion, IVH risk factors, and the predictive value of the relevant factors for IVH were analyzed. Results The IVH group had lower birth weight, hemoglobin levels on admission, and days of age at first blood transfusion and higher 5-min Apgar score ≤ 7 points and early transfusion rate. Spontaneous delivery and 5-min Apgar score ≤ 7 points were risk factors for IVH. Birth weight and days of age at first blood transfusion had predictive value for IVH in VLBW and ELBW infants. Conclusions The younger the days of age at first blood transfusion, the higher the IVH risk. It is necessary to delay the days of age at first blood transfusion and reduce early blood transfusion.