Effect of cuff inflation with lidocaine, saline, and air on tracheal tube cuff pressure during laparoscopic resection of colorectal neoplasms: a randomized clinical trial.

BACKGROUND: Tracheal tube cuff pressure will increase after pneumoperitoneum when the cuff is inflated with air, high pressure can cause tracheal mucosal damage. This prospective trial aimed to assess if inflating with normal saline or lidocaine can prevent increase of tracheal tube cuff pressure and tracheal mucosal damage in laparoscopic surgeries with general anesthesia. Whether changes of tracheal tube cuff transverse diameter (CD) can predict changes of tracheal tube cuff pressure. METHODS: Ninety patients scheduled for laparoscopic resection of colorectal neoplasms under general anesthesia were randomly assigned to groups air (A), saline (S) or lidocaine (L). Endotracheal tube cuff was inflated with room-temperature air in group A (n = 30), normal saline in group S (n = 30), 2% lidocaine hydrochloride injection in group L (n = 30). After intubation, tracheal tube cuff pressure was monitored by a calibrated pressure transducers, cuff pressure was adjusted to 25 cmH2O (T0.5). Tracheal tube cuff pressure at 15 min after pneumoperitoneum (T1) and 15 min after exsufflation (T2) were accessed. CD were measured by ultrasound at T0.5 and T1, the ability of ΔCD (T1-0.5) to predict cuff pressure was accessed. Tracheal mucous injury at the end of surgery were also recorded. RESULTS: Tracheal tube cuff pressure had no significant difference among the three groups at T1 and T2. ΔCD had prediction value (AUC: 0.92 [95% CI: 0.81-1.02]; sensitivity: 0.99; specificity: 0.82) for cuff pressure. Tracheal mucous injury at the end of surgery were 0 (0, 1.0) in group A, 0 (0, 1.0) in group S, 0 (0, 0) in group L (p = 0.02, group L was lower than group A and S, p = 0.03 and p = 0.04). CONCLUSIONS: Compared to inflation with air, normal saline and 2% lidocaine cannot ameliorate the increase of tracheal tube cuff pressure during the pneumoperitoneum period under general anesthesia, but lidocaine can decrease postoperative tracheal mucosa injury. ΔCD measured by ultrasound is a predictor for changes of tracheal tube cuff pressure. TRIAL REGISTRATION: Chinese Clinical Trial Registry, identifier: ChiCTR2100054089, Date: 08/12/2021.

Association between swallowing dynamics, tongue pressure and pulmonary function in patients with idiopathic pulmonary fibrosis.

BACKGROUND: Swallowing is a complex process that requires the coordination of muscles in the mouth, pharynx, larynx, and esophagus. Dysphagia occurs when a person has difficulty swallowing. In the case of subjects with respiratory diseases, the presence of oropharyngeal dysphagia potentially increases lung disease exacerbations, which can lead to a rapid decline in lung function. This study aimed to analyze the swallowing of patients with idiopathic pulmonary fibrosis (IPF). METHODS: Patients with IPF were evaluated using the Eating Assessment Tool (EAT-10), tongue pressure, the Timed Water Swallow Test (TWST), and the Test of Mastication and Swallowing Solids (TOMASS). The findings were related to dyspnea severity assessed by the modified Medical Research Counsil (mMRC) score; the nutritional status screened with Mini Nutritional Assessment (MNA) tool; and pulmonary function tests, specifically spirometry and measurement of the diffusing capacity for carbon monoxide (DLCO), the maximal inspiratory pressure (PImax), and the maximal expiratory pressure (PEmax). RESULTS: The sample consisted of 34 individuals with IPF. Those who exhibited swallowing modifications scored lower on the MNA than those who did not (9.6 ± 0.76 vs. 11.64 ± 0.41 points; mean difference 1.98 ± 0.81 points; p = 0.02). They also showed poorer lung function when considering the predicted force vital capacity (FVC; 81.5% ± 4.61% vs. 61.87% ± 8.48%; mean difference 19.63% ± 9.02%; p = 0.03). The speed of liquid swallowing was altered in 31of 34 of the evaluated subjects (91.1%). The number of liquid swallows correlated significantly with the forced expiratory volume in 1 s (FEV1)/FVC ratio (r = 0.3; p = 0.02). Solid eating and swallowing assessed with the TOMASS score correlated with lung function. The number of chewing cycles correlated negatively with PImax% predicted (r = -0.4; p = 0.0008) and PEmax% predicted (r = -0.3; p = 0.02). FVC% predicted correlated with increased solid swallowing time (r = -0.3; p = 0.02; power = 0.6). Swallowing solids was also impacted by dyspnea. CONCLUSION: Patients with mild-to-moderate IPF can present feeding adaptations, which can be related to the nutritional status, lung function, and the severity of dyspnea.

Shear wave elastography of transverse carpal ligament increased with simulated carpal tunnel pressure.

BACKGROUND: Elevation of carpal tunnel pressure is known to be associated with carpal tunnel syndrome. This study aimed to correlate the shear wave elastography in the transverse carpal ligament (TCL) with carpal tunnel pressures using a cadaveric model. METHODS: Eight human cadaveric hands were dissected to evacuate the tunnels. A medical balloon was inserted into each tunnel and connected to a pressure regulator to simulate tunnel pressure in the range of 0-210 mmHg with an increment of 30 mmHg. Shear wave velocity and modulus was measure in the middle of TCL. RESULTS: SWV and SWE were significantly dependent on the pressure levels (p < 0.001), and positively correlated to the tunnel pressure (SWV: R = 0.997, p < 0.001; SWE: R = 0.996, p < 0.001). Regression analyses showed linear relationship SWV and pressure (SWV = 4.359 + 0.0263 * Pressure, R2 = 0.994) and between SWE and pressure (SWE = 48.927 + 1.248 * Pressure, R2 = 0.996). CONCLUSION: The study indicated that SWV and SWE in the TCL increased linearly as the tunnel pressure increased within the current pressure range. The findings suggested that SWV/SWE in the TCL has the potential for prediction of tunnel pressure and diagnosis of carpal tunnel syndrome.

Preparation of Erlotinib hydrochloride nanoparticles (anti-cancer drug) by RESS-C method and investigating the effective parameters.

The size of the drug particles is one of the essential factors for the proper absorption of the drug compared to the dose of the drug. When particle size is decreased, drug uptake into the body increases. Recent studies have revealed that the rapid expansion of supercritical solution with cosolvent plays a significant role in preparing micron and submicron particles. This paper examines the preparation of Erlotinib hydrochloride nanoparticles using a supercritical solution through the cosolvent method for the first time. An examination of the parameters of temperature (318-338 K), pressures (15-25 MPa) and nozzle diameter (300-700 µm) was investigated by Box-Behnken design, and their respective effects on particle size revealed that the nozzle diameter has a more significant impact on particle size than the other parameters. The smallest particles were produced at temperature 338 K, pressure 20 MPa, and nozzle diameter 700 µm. Besides, the ERL nanoparticles were characterized using SEM, DLS, XRD, FTIR, and DSC analyses. Finally, the results showed that the average size of the ERL particles decreased from 31.6 µm to 200-1100 nm.

Low Pressure versus Standard Pressure Pneumoperitoneum in Laparoscopic Appendectomy: A Randomized Controlled Trial.

BACKGROUND: The creation of pneumoperitoneum using higher pressure is believed to be associated with increased postoperative abdominal pain. AIM: This study aimed to compare postoperative abdominal pain following low pressure laparoscopic appendectomy and standard pressure laparoscopic appendectomy. METHODS: This was a prospective, double-blind, randomized controlled trial of 54 patients aged between 18 and 56 years with clinical and/or radiologic diagnosis of acute appendicitis. The patients were randomly allocated to two groups: low pressure laparoscopic appendectomy (n = 26) and standard pressure laparoscopic appendectomy (n = 28). The intra-abdominal pressure was kept in either low pressure (9 mm Hg) or standard pressure (13 mm Hg). Abdominal and shoulder pain scores were assessed using the visual analog scale at 6 hours and 3 days post procedure. Postoperative analgesia requirement, duration of surgery, complications, and hospital stay were recorded. RESULTS: Both groups match for the demographic parameters. Three patients required conversion from low to standard pressure. There was no difference between the two groups in terms of abdominal pain (P = 0.86) and shoulder pain (P = 0.33), duration of surgery (P = 0.51), complications (P = 0.17), and length of hospital stay (P = 0.83). CONCLUSION: The use of low pressure pneumoperitoneum did not reduce the incidence of abdominal pain in patients who had laparoscopic appendectomy. Patients with acute appendicitis can be treated with either low or normal pressure pneumoperitoneum depending on the experience of the surgeon.

Intrarenal pressure with hand-pump or pressurized-bag irrigation: randomized clinical trial at retrograde intrarenal surgery.

BACKGROUND: The aim was to ascertain the impact of irrigation technique on human intrarenal pressure during retrograde intrarenal surgery. METHODS: A parallel randomized trial recruited patients across three hospital sites. Patients undergoing retrograde intrarenal surgery for renal stone treatment with an 11/13-Fr ureteral access sheath were allocated randomly to 100 mmHg pressurized-bag (PB) or manual hand-pump (HP) irrigation. The primary outcome was mean procedural intrarenal pressure. Secondary outcomes included maximum intrarenal pressure, variance, visualization, HP force of usage, procedure duration, stone clearance, and clinical outcomes. Live intrarenal pressure monitoring was performed using a COMETTMII pressure guidewire, deployed cystoscopically to the renal pelvis. The operating team was blinded to the intrarenal pressure. RESULTS: Thirty-eight patients were randomized between July and November 2023 (trial closure). The final analysis included 34 patients (PB 16; HP 18). Compared with PB irrigation, HP irrigation resulted in significantly higher mean intrarenal pressure (mean(s.d.) 62.29(27.45) versus 38.16(16.84) mmHg; 95% c.i. for difference in means (MD) 7.97 to 40.29 mmHg; P = 0.005) and maximum intrarenal pressure (192.71(106.23) versus 68.04(24.16) mmHg; 95% c.i. for MD 70.76 to 178.59 mmHg; P < 0.001), along with greater variance in intrarenal pressure (log transformed) (6.23(1.59) versus 4.60(1.30); 95% c.i. for MD 0.62 to 2.66; P = 0.001). Surgeon satisfaction with procedural vision reported on a scale of 10 was higher with PB compared with HP irrigation (mean(s.d.) 8.75(0.58) versus 6.28(1.27); 95% c.i. for MD 1.79 to 3.16; P < 0.001). Subjective HP usage force did not correlate significantly with transmitted intrarenal pressure (Pearson R = -0.15, P = 0.57). One patient (HP arm) developed urosepsis. CONCLUSION: Manual HP irrigation resulted in higher and more fluctuant intrarenal pressure trace (with inferior visual clarity) than 100-mmHg PB irrigation. REGISTRATION NUMBER: osf.io/jmg2h (https://osf.io/).

Validation of continuous intraabdominal pressure measurement: feasibility and accuracy assessment using a capsular device in in-vivo studies.

BACKGROUND: Monitoring Intraabdominal Pressure (IAP) is essential in critical care, as elevated IAP can lead to severe complications, including Abdominal Compartment Syndrome (ACS). Advances in technology, such as digital capsules, have opened new avenues for measuring IAP non-invasively. This study assesses the feasibility and effectiveness of using a capsular device for IAP measurement in an animal model. METHOD: In our controlled experiment, we anesthetized pigs and simulated elevated IAP conditions by infusing CO2 into the peritoneal cavity. We compared IAP measurements obtained from three different methods: an intravesical catheter (IAPivp), a capsular device (IAPdot), and a direct peritoneal catheter (IAPdir). The data from these methods were analyzed to evaluate agreement and accuracy. RESULTS: The capsular sensor (IAPdot) provided continuous and accurate detection of IAP over 144 h, with a total of 53,065,487 measurement triplets recorded. The correlation coefficient (R²) between IAPdot and IAPdir was excellent at 0.9241, demonstrating high agreement. Similarly, IAPivp and IAPdir showed strong correlation with an R² of 0.9168. CONCLUSION: The use of capsular sensors for continuous and accurate assessment of IAP marks a significant advancement in the field of critical care monitoring. The high correlation between measurements from different locations and methods underscores the potential of capsular devices to transform clinical practices by providing reliable, non-invasive IAP monitoring.

Quality Assessment of Fish Oil Obtained after Enzymatic Hydrolysis of a Mixture of Rainbow Trout (Oncorhynchus mykiss) and Atlantic Salmon (Salmo salar) Rest Raw Material Pretreated by High Pressure.

Utilization of fish rest raw material for fish oil extraction has received interest with the increasing demand for sustainable food sources. Enzymatic hydrolysis is an efficient method for the extraction of value-added compounds, but its effectiveness may be enhanced by high-pressure processing (HPP). However, HPP can induce lipid oxidation, affecting the quality of the oil. This study aimed to evaluate the quality of fish oil obtained after enzymatic hydrolysis of a mixture of rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar) rest raw material pretreated by HPP. Six pretreatments were tested prior to enzymatic hydrolysis; 200 MPa × 4 min, 200 MPa × 8 min, 400 MPa × 4 min, 400 MPa × 8 min, 600 MPa × 4 min, and 600 MPa × 8 min. The oil samples were analyzed for lipid oxidation parameters, free fatty acid content, fatty acid composition, and color changes over 8 weeks. The results confirmed that HPP may induce lipid oxidation and revealed significant influence of HPP parameters on lipid oxidation, with higher pressures leading to increased oxidation. Fatty acid composition varied among samples, but it was not substantially affected by HPP.

Organic solvents-free and ambient-pressure drying melamine formaldehyde resin aerogels with homogeneous structures, outstanding mechanical strength and flame retardancy.

Atmospheric drying method for fabricating aerogels is considered the most promising way for casting aerogels on a large scale. However, the organic solvent exchange, remaining environmental pollution risk, is a crucial step in mitigating the impact of surface tension during the atmospheric drying process, especially for wet gel formed through the alkoxy-derived sol-gel process, such as melamine-formaldehyde resin (MF) aerogel. Herein, a tough polymer-assisted in situ polymerization was proposed to fabricate MF resin aerogel with a combination of mechanical toughness and strength, enabling it to withstand the capillary force during water evaporation. The monolithic MF resin aerogel through the sol-gel method can be directly prepared without additional network strengthening or organic solvent exchange. The resulting MF resin aerogel exhibits a homogeneous as well as hierarchical structure with macropores and mesopores (~6 µm and ~5 nm), high compressive modulus of 31.8 MPa, self-extinguishing property, and high-temperature thermal insulation with 97 % heat decrease for butane flame combustion. This work presents a straightforward and environmentally friendly method for fabricating MF resin aerogels with nanostructures and excellent performance in open conditions, exhibiting various applications.

Relationship between changes in muscle stiffness after a comfortable massage and the massage pressure.

INTRODUCTION: This study aimed to determine whether massage pressure on the target muscles (biceps brachii muscle [BB] and the medial head of the gastrocnemius muscle [MG]) is related to the massage effect (reducing muscle stiffness). METHOD: Nine healthy participants participated in this study. A physiotherapist massaged the upper arms and lower legs of participants on a rigid desk in a laboratory. Massage was delivered for 10 min with a 3-min rest. The shear modulus (i.e., the muscle stiffness), assessed by shear wave elastography, was measured at various time points (before [PRE], immediately after [POST], and 5 [POST-5], 10, 15, and 20 min after the massage). The massage pressure data (N) were obtained only during massage by force plate sensors. RESULTS: The BB shear modulus was significantly reduced POST massage. The MG shear modulus significantly reduced POST massage and remained clearly reduced until POST-5. There was a negative correlation between the total massage pressure and the % change in the shear modulus in both muscles. DISCUSSION: Since the spindle (BB) and pennate (MG) muscles have structural differences, our results suggest that these differences may affect the pattern of changes in the shear modulus in response to massage. CONCLUSION: Massage pressure is related to the massage effect (reducing muscle stiffness), and its relationships to POST are not related to the differences in the morphologies of the spindle (BB) and pennate muscles (MG). However, differences in the morphologies of the spindle and pennate muscles may cause differences in the duration of the massage effects.

Impact of Insertion Speed, Depth, and Robotic Assistance on Cochlear Implant Insertion Forces and Intracochlear Pressure: A Scoping Review.

Cochlear implants are crucial for addressing severe-to-profound hearing loss, with the success of the procedure requiring careful electrode placement. This scoping review synthesizes the findings from 125 studies examining the factors influencing insertion forces (IFs) and intracochlear pressure (IP), which are crucial for optimizing implantation techniques and enhancing patient outcomes. The review highlights the impact of variables, including insertion depth, speed, and the use of robotic assistance on IFs and IP. Results indicate that higher insertion speeds generally increase IFs and IP in artificial models, a pattern not consistently observed in cadaveric studies due to variations in methodology and sample size. The study also explores the observed minimal impact of robotic assistance on reducing IFs compared to manual methods. Importantly, this review underscores the need for a standardized approach in cochlear implant research to address inconsistencies and improve clinical practices aimed at preserving hearing during implantation.

Application Analysis of Low-Pressure Perfusion Combined with Occluder in Holmium Laser Lithotripsy for Patients with Middle and Upper Ureteral Calculi.

BACKGROUND: Ureteroscopic holmium laser lithotripsy has become one of the main methods of treating ureteral calculi. However, in the treatment of middle and upper ureteral calculi, ureteroscopy is difficult to operate owing to the high location of calculi. Thus, how to improve the treatment effect and reduce the stone migration has become the focus in clinical settings. On this basis, we evaluated the application effect of low-pressure perfusion combined with occluder in holmium laser lithotripsy for patients with middle and upper ureteral calculi. METHODS: This retrospective study selected 107 patients with middle and upper ureteral calculi who underwent low-pressure perfusion combined with ureteroscopic holmium laser lithotripsy from January 2021 to December 2022. We excluded 7 patients who did not meet the criteria, and ultimately included 100 patients. According to whether the occluder was used during the surgery, 100 patients were divided into groups A (n = 52, occluder) and B (n = 48, without occluder). The stone-migration rate during surgery, stone-clearance rate at 3 months after surgery, perioperative indicators, postoperative complication rate, and postoperative quality of life between the two groups were compared. RESULTS: The stone-migration rate in group A was significantly lower than that in group B, with statistically significant difference (p < 0.05). Both groups had no significant difference in stone-clearance rate at 3 months after surgery (p > 0.05). Group A had a significantly lower index of EuroQol (EQ) Five Dimensions Questionnaire and significantly higher score of EQ-Visual Analogue Scale than group B (all p < 0.001). CONCLUSIONS: Compared with the simple application of low-pressure perfusion, the combined application of low-pressure perfusion and occluder in ureteroscopic holmium laser lithotripsy can effectively reduce the stone migration and improve the postoperative quality of life.

Comparison of the Kron technique and digital manometry for measuring intra-abdominal pressure in emergency department patients diagnosed with ileus.

BACKGROUND: Numerous measurement techniques for intra-abdominal pressure have been explored, with the Kron Technique established as the gold standard. Despite its prominence, the search for alternative methods persists due to its lengthy application time, the requirement for additional equipment, and overall impracticality. This study investigated a quicker, more accessible method for effective intra-abdominal pressure measurement in the emergency department. It aimed to compare intra-abdominal pressure measurements in patients diagnosed with ileus using a digital manometer and the Kron Technique. METHODS: Conducted from October 2022 to February 2023, this single-center, prospective, single-blind method comparison study involved patients diagnosed with ileus at a tertiary emergency department. Intra-abdominal pressure was measured using both the Kron Technique and a digital manometer by separate practitioners blinded to the study results. RESULTS: The study included 30 patients. No statistically significant difference was observed in the intra-abdominal pressure measurements between the two methods (p<0.237). A very strong correlation existed between the two methods (Spearman's Rho = 0.998). Bland-Altman analysis showed a bias value of 0.091 mmHg for the digital manometer, with upper and lower agreement limits of -0.825 and 1.007 mmHg, respectively. The measurement time was significantly shorter with the digital manometer than with the Kron Technique (15 vs. 390.5 seconds; p<0.001). CONCLUSION: We believe that the intra-abdominal pressure measurement technique using a digital manometer is a method that can be effectively employed by healthcare professionals in emergency departments. This technique offers ease of use, requires minimal equipment, provides rapid results, and delivers reliable measurement values compared to the Kron Technique.

How effective is proximal fibular osteotomy in redistributing joint pressures? Insights from an HTO comparative in-silico study.

BACKGROUND: Knee osteoarthritis (KOA) represents a widespread degenerative condition among adults that significantly affects quality of life. This study aims to elucidate the biomechanical implications of proximal fibular osteotomy (PFO), a proposed cost-effective and straightforward intervention for KOA, comparing its effects against traditional high tibial osteotomy (HTO) through in-silico analysis. METHODS: Using medical imaging and finite element analysis (FEA), this research quantitatively evaluates the biomechanical outcomes of a simulated PFO procedure in patients with severe medial compartment genu-varum, who have undergone surgical correction with HTO. The study focused on evaluating changes in knee joint contact pressures, stress distribution, and anatomical positioning of the center of pressure (CoP). Three models are generated for each of the five patients investigated in this study, a preoperative original condition model, an in-silico PFO based on the same original condition data, and a reversed-engineered HTO in-silico model. RESULTS: The novel contribution of this investigation is the quantitative analysis of the impact of PFO on the biomechanics of the knee joint. The results provide mechanical evidence that PFO can effectively redistribute and homogenize joint stresses, while also repositioning the CoP towards the center of the knee, similar to what is observed post HTO. The findings propose PFO as a potentially viable and simpler alternative to conventional surgical methods for managing severe KOA, specifically in patients with medial compartment genu-varum. CONCLUSION: This research also marks the first application of FEA that may support one of the underlying biomechanical theories of PFO, providing a foundation for future clinical and in-silico studies.

Anesthesiological and surgical perspectives on using 8 mmHg versus 12 mmHg pneumoperitoneum pressures during robotic radical prostatectomy: Results of a prospective randomized study.

BACKGROUND: This study aims to compare the effects of 8 mmHg and 12 mmHg pneumoperitoneum (PNP) pressures on operative, postoperative, and anesthesiological parameters in robot-assisted laparoscopic radical prostatectomy (RARP). METHODS: In this prospective study, 43 patients undergoing RARP performed by a single experienced surgeon were randomly assigned to either the low-pressure group (8 mmHg - Group I) or the standard-pressure group (12 mmHg - Group II). We evaluated the operative and postoperative parameters from both urological and anesthesiological perspectives. All patients were treated using the AirSeal® insufflation system. RESULTS: No statistically significant differences were observed between the groups in terms of console time, estimated blood loss, time to first flatus, or hospital length of stay. PNP was increased due to bleeding in six patients in the 8 mmHg group and two patients in the 12 mmHg group. Except for the heart rate measured five minutes after the initial incision, there were no observed differences between the groups in terms of blood pressure, ventilation, and administered medications. The heart rate was significantly lower in Group I (54.4 vs. 68.8, p=0.006). Additionally, during the surgery, the number of manipulations performed by the anesthesiologists, including drug administrations and ventilator management, was significantly lower in Group I (6.1 vs. 9.6, p=0.041). CONCLUSION: In RARP, while the 8 mmHg PNP pressure does not demonstrate differences in operative parameters compared to the 12 mmHg pressure, it offers the advantage of requiring fewer anesthetic interventions, thus minimizing the impact on cardiovascular and respiratory systems.

In situ cleaning of foulants by gas scouring on the membrane-electrode in an electro-membrane bioreactor.

Low-maintenance membrane cleaning is essential for the stable operation of membrane bioreactors. This work proposes an in-situ electrical-cleaning method using an electro-MBR. When the applied bias was transiently increased, the membrane flux recovered rapidly because of the scouring effect from gas evolution reactions. The exfoliation of the cake layer induced by gas scouring played a major role in mitigating membrane fouling, recovering the transmembrane pressure (TMP) by 88.6 % under optimal conditions. Membrane modules did not require replacement during the operation period due to the efficacy of electrical cleaning, with the TMP varying between 37.5 % and 62.5 % of the ultimate pressure requiring change of the membrane modules. Despite the increase in power consumption of 0.66 Wh·m-3 due to the additional applied bias, there was no need for chemical additives or manual maintenance. Therefore, the electrical cleaning method enhanced the service life and reduced the maintenance costs of the electro-MBR.

Mechanism of acoustic pressure spectrum shifting toward lower frequencies in applied current thermoacoustic imaging.

Objective. Thermoacoustic tomography (TAT) is a promising imaging technique used for early cancer diagnosis, tumor therapy, animal study and brain imaging. Although it is widely known that the TAT frequency response depends on the pulse width of the source and the size of the object, a thorough comprehension of the quantitative frequency modulation in TAT and the mechanism governing the shift in the thermoacoustic pressure spectrum towards lower frequencies with respect to the excitation source is still lacking. This study aims to understand why the acoustic pressure spectrum and the final voltage signals shift towards lower frequencies in TAT.Approach. We employed a linear time-invariant model. In the proposed model, the applied current thermoacoustic imaging (ACTAI) process is divided into the thermoacoustic stage and the acoustoelectric stage. These two stages are characterized by the thermoacoustic transfer function(TATF) and the transducer transfer function (TDTF), respectively. We confirmed the effectiveness of our model through a rigorous examination involving both simulations and experiments.Main results. Simulation results indicate that the TATF behaves as a low-pass filter. The inherent low-pass nature induces a shift towards low frequencies in the acoustic pressure spectrum. Experiments further confirm this behavior, demonstrating that the final electrical voltage also shifts towards low frequencies. Notably, employing the proposed model, there is a remarkable consistency between the main frequency bands of the synthesized and measured final voltage spectrum.Significance. The proposed model thoroughly explains how the TATF causes shifts to low frequencies in both the acoustic pressure spectrum and the final voltage spectrum in TAT. These insights deepen our understanding of optimizing TAT systems in the frequency domain, including aspects like filter design and transducer selection. Furthermore, we underscore the potential significance of this discovery for medical applications, particularly in the context of cancer diagnosis.

Pneumothorax risk reduction during CT-guided lung biopsy - Effect of fluid application to the pleura before lung puncture and the gravitational effect of pleural pressure.

PURPOSE: This study investigated strategies to reduce pneumothorax risk in CT-guided lung biopsy. The approach involved administering 10 ml of 1 % lidocaine fluid in the subpleural or pleural space before lung puncture and utilizing the gravitational effect of pleural pressure with specific patient positioning. METHOD: We retrospectively analyzed 72 percutaneous CT-guided lung biopsies performed at a single center between January 2020 and April 2023. These were grouped based on fluid administration during the biopsy and whether the biopsies were conducted in dependent or non-dependent lung regions. Confounding factors like patient demographics, lesion characteristics, and procedural details were assessed. Patient characteristics and the occurrence of pneumothoraces were compared using a Kurskal-Wallis test for continuous variables and a Fisher's exact test for categorical variables. Multivariable logistic regression was used to identify potential confounders. RESULTS: Subpleural or pleural fluid administration and performing biopsies in dependent lung areas were significantly linked to lower peri-interventional pneumothorax incidence (n = 15; 65 % without fluid in non-dependent areas, n = 5; 42 % without fluid in dependent areas, n = 5; 36 % with fluid in non-dependent areas,n = 0; 0 % with fluid in dependent areas; p = .001). Even after adjusting for various factors, biopsy in dependent areas and fluid administration remained independently associated with reduced pneumothorax risk (OR 0.071, p<=.01 for lesions with fluid administration; OR 0.077, p = .016 for lesions in dependent areas). CONCLUSIONS: Pre-puncture fluid administration to the pleura and consideration of gravitational effects during patient positioning can effectively decrease pneumothorax occurrences in CT-guided lung biopsy.

Effect of gradient pressure therapy on the prevention of chemotherapy-induced peripheral neuropathy in patients with breast cancer.

PURPOSE: To investigate the effect of gradient pressure therapy on the prevention of chemotherapy-induced peripheral neuropathy (CIPN) and improvement in activities of daily living (ADL) in patients with breast cancer. METHODS: Eighty female patients with breast cancer treated at Tangshan People's Hospital between October 2022 and July 2023 were selected as research participants and divided into control and intervention, with 40 patients in each group. The control group received routine treatment and care, whereas the intervention group received gradient pressure therapy based on routine treatment and care. Incidence of peripheral neuropathy and the degree of impact on ADL between the two groups were compared after the intervention for cycles 2, 4, and 6. RESULTS: There was no significant difference in the general information between the two groups (P > 0.05). After two intervention cycles, there was no significant difference in the incidence of CIPN, various dimensions of Chemotherapy-Induced Peripheral Neuropathy Assessment Tool (CIPNAT), and total scores between the two groups (P > 0.05). After four intervention cycles, the two groups had a statistically significant difference in the incidence of CIPN, sensory dimension, general activity dimension, and total CIPNAT score (P < 0.05). After six intervention cycles, there was a significant difference in the incidence of CIPN, sensory dimension, fine activity dimension, general activity dimension, and total CIPNAT score between the two groups (P < 0.05), while there was no significant difference in the other dimensions (P > 0.05). CONCLUSIONS: Gradient pressure therapy can effectively prevent or alleviate peripheral neuropathy in patients with breast cancer undergoing chemotherapy and improve their ability to perform ADL. Thus, it is safe, effective, and worthy of clinical application. TRIAL REGISTRATION: RMYY-LLKS-2022-054.

Trans-electrode pressure of gas-diffusion electrodes significantly influencing the electrochemical hydrogen peroxide production.

Hydrogen peroxide (H2O2) synthesis by electrochemical two-electron oxygen reduction has garnered increasing interest as a wide range of potential applications. Gas diffusion electrodes (GDEs) can effectively promote the H2O2 production efficiency by overcoming the oxygen mass transfer limitations but strongly influenced by the electrowetting process along the long-term operation. In this study, the effect of trans-electrode pressure (TEP) of GDE cathode on the electrowetting process was further elucidated. We controlled the TEP values of four types of GDEs: two Ni-based GDEs and two carbon cloth GDEs prepared by hot-pressing or brushing carbon black. SBA-15 was further used to regulate the microstructure of one Ni-based GDE. It was found that an optimal range of TEP occurred for all tested GDEs in terms of the max. concentration, the yield efficiency, the energy consumption, and the stability because TEP may change the triple-phase interface and influence the anti-electrowetting effect. The porosity of hot-pressed Ni GDE can maintain the TEP window and thus enhance the production of H2O2, likely via creating oxygen-containing functional groups and a bimodal pore structure on the electrode, revealed with several characterization techniques including SEM, CA, XPS, Raman spectra, CV and EIS. The porous Ni GDE presented an efficient and stable production of H2O2 for 10 cycles: yielding H2O2 at 4393.2-4602.2 mmol m-2 h-1 with current efficiencies of 94.2-98.7%. The best accumulated H2O2 concentration can reach up to 3.58 ωt% H2O2 at 10 h. The results provide an important reference for the industrial scaleup of electro-production of H2O2 with GDEs.