Effect of ultrasound pretreatment on wood prior to vacuum drying

The influence of ultrasonic pretreatment prior to vacuum drying of Chinese fir specimens was examined in this work. In the pretreatments, wood samples were immerged in a distilled water bath and were treated using two wave frequencies for four different elapsed times to investigate effects of ultrasonic frequency and treatment duration. Then the wood samples were vacuum-dried at 80°C and absolute pressure of 0,05 MPa. After the pretreatment, microscopic analysis was carried out on the wood samples to check micro-cracks, the loss of extractives from the cell walls and other micro-structural changes on the wood. Results show that the ultrasonic treatment prior to vacuum drying significantly shortened the wood drying time. The drying time decreased with increase in the wave frequency and the treatment time. Furthermore, ultrasound pretreatment tended to reduce the content of extractives in the wood cell walls and cause cell-wall micro-cracking

Cardiac-derived CTRP9 protects against myocardial ischemia/reperfusion injury via calreticulin-dependent inhibition of apoptosis.

Cardiokines play an essential role in maintaining normal cardiac functions and responding to acute myocardial injury. Studies have demonstrated the heart itself is a significant source of C1q/TNF-related protein 9 (CTRP9). However, the biological role of cardiac-derived CTRP9 remains unclear. We hypothesize cardiac-derived CTRP9 responds to acute myocardial ischemia/reperfusion (MI/R) injury as a cardiokine. We explored the role of cardiac-derived CTRP9 in MI/R injury via genetic manipulation and a CTRP9-knockout (CTRP9-KO) animal model. Inhibition of cardiac CTRP9 exacerbated, whereas its overexpression ameliorated, left ventricular dysfunction and myocardial apoptosis. Endothelial CTRP9 expression was unchanged while cardiomyocyte CTRP9 levels decreased after simulated ischemia/`reperfusion (SI/R) in vitro. Cardiomyocyte CTRP9 overexpression inhibited SI/R-induced apoptosis, an effect abrogated by CTRP9 antibody. Mechanistically, cardiac-derived CTRP9 activated anti-apoptotic signaling pathways and inhibited endoplasmic reticulum (ER) stress-related apoptosis in MI/R injury. Notably, CTRP9 interacted with the ER molecular chaperone calreticulin (CRT) located on the cell surface and in the cytoplasm of cardiomyocytes. The CTRP9-CRT interaction activated the protein kinase A-cAMP response element binding protein (PKA-CREB) signaling pathway, blocked by functional neutralization of the autocrine CTRP9. Inhibition of either CRT or PKA blunted cardiac-derived CTRP9\u27s anti-apoptotic actions against MI/R injury. We further confirmed these findings in CTRP9-KO rats. Together, these results demonstrate that autocrine CTRP9 of cardiomyocyte origin protects against MI/R injury via CRT association, activation of the PKA-CREB pathway, ultimately inhibiting cardiomyocyte apoptosis

Esophageal pressure monitoring and its clinical significance in severe blast lung injury

BackgroundThe incidence of blast lung injury (BLI) has been escalating annually due to military conflicts and industrial accidents. Currently, research into these injuries predominantly uses animal models. Despite the availability of various models, there remains a scarcity of studies focused on monitoring respiratory mechanics post-BLI. Consequently, our objective was to develop a model for monitoring esophageal pressure (Pes) following BLI using a biological shock tube (BST), aimed at providing immediate and precise monitoring of respiratory mechanics parameters post-injury.MethodsSix pigs were subjected to BLI using a BST, during which Pes was monitored. We assessed vital signs; conducted blood gas analysis, hemodynamics evaluations, and lung ultrasound; and measured respiratory mechanics before and after the inflicted injury. Furthermore, the gross anatomy of the lungs 3 h post-injury was examined, and hematoxylin and eosin staining was conducted on the injured lung tissues for further analysis.ResultsThe pressure in the experimental section of the BST reached 402.52 ± 17.95 KPa, with a peak pressure duration of 53.22 ± 1.69 ms. All six pigs exhibited an anatomical lung injury score ≥3, and pathology revealed classic signs of severe BLI. Post-injury vital signs showed an increase in HR and SI, along with a decrease in MAP (p < 0.05). Blood gas analyses indicated elevated levels of Lac, CO2-GAP, A-aDO2, HB, and HCT and reduced levels of DO2, OI, SaO2, and OER (p < 0.05). Hemodynamics and lung ultrasonography findings showed increased ELWI, PVPI, SVRI, and lung ultrasonography scores and decreased CI, SVI, GEDI, and ITBI (p < 0.05). Analysis of respiratory mechanics revealed increased Ppeak, Pplat, Driving P, MAP, PEF, Ri, lung elastance, MP, Ptp, Ppeak − Pplat, and ΔPes, while Cdyn, Cstat, and time constant were reduced (p < 0.05).ConclusionWe have successfully developed a novel respiratory mechanics monitoring model for severe BLI. This model is reliable, repeatable, stable, effective, and user-friendly. Pes monitoring offers a non-invasive and straightforward alternative to blood gas analysis, facilitating early clinical decision-making. Our animal study lays the groundwork for the early diagnosis and management of severe BLI in clinical settings

Clinical Effects of Sacubitril/Valsartan Combined with Dapagliflozin in Patients with Diabetes and ST-segment Elevation Myocardial Infarction

Objectives: This study was aimed at observing the clinical effects of sacubitril/valsartan combined with dapagliflozin on cardiac function and ventricular remodeling in patients with type 2 diabetes and ST-segment elevation myocardial infarction (STEMI). Methods: Between May 2019 and May 2022, we retrospectively analyzed 57 patients with diabetes and STEMI receiving percutaneous coronary intervention: 32 patients receiving sacubitril/valsartan and dapagliflozin tablets comprised the observation group and 25 patients receiving angiotensin converting enzyme inhibition (ACEI) or angiotensin receptor blockers ARB) in combination with other hypoglycemic drugs comprised the control group. We compared the left ventricular end diastolic diameter (LVEDD), right ventricular end diastolic diameter (RVEDD), left ventricular ejection fraction (LVEF), N-terminal pro-B-type natriuretic peptide (NT-pro BNP), and noninvasive hemodynamic parameters at baseline and 3–6 months after treatment between the groups. Results: Before treatment, the parameters were similar between the observation group and control group. However, after 3−6 months of treatment, serum NT-pro BNP levels showed a greater decline in the observation group than the control group. Moreover, the LVEDD and LVEF improved more substantially in the observation group than the control group (P0.05). After treatment, in the observation group, the cardiac index (CI) and cardiac output (CO) were significantly higher, and the thoracic fluid conduction (TFC) and systemic vascular resistance index (SVRI) were significantly lower, than those in the control group (P<0.05). Conclusions: Sacubitril/valsartan combination with dapagliflozin exerted better effects than ACEI or ARB with other hypoglycemic drugs in improving cardiac function and ventricular remodeling in patients with diabetes and STEMI

Correlation between HBsAg, prothrombin time activity, and indocyanine green retention rate at 15 minutes in patients with HBeAg-positive chronic HBV infection

ObjectiveTo investigate the correlation between HBsAg, prothrombin time activity (PTA), and indocyanine green retention rate at 15 minutes (ICG R15) in patients with HBeAg-positive chronic HBV infection. MethodsA total of 92 patients with HBeAg-positive chronic HBV infection who were admitted to The First Hospital of Lanzhou University from December 2015 to April 2016 were enrolled and divided into chronic hepatitis B (CHB) group (24 patients), compensated liver cirrhosis group (38 patients), and decompensated liver cirrhosis group (30 patients). Serum HBsAg quantitation, PTA test, and liver reserve function test (ICG R15) were performed for all patients. The chi-square test was used for comparison of categorical data between groups, an analysis of variance was used for comparison of continuous data between multiple groups, and a Pearson correlation analysis was also performed. ResultsThere were significant differences between the three groups in serum HBsAg quantitation (3.82±0.43 log10IU/ml vs 2.88±0.36 log10IU/ml vs 2.60±0.27 log10IU/ml, F=25.19, P＜0.001), ICG R15 (7.51%±3.10% vs 9.57%±8.18% vs 24.13%±14.28%, F=24.00, P=0.001), and PTA (8100%±1762% vs 83.08%±9.64% vs 62.32%±16.90%, F=13.42, P=0.009). The correlation analysis showed that PTA was negatively correlated with ICG R15 in all three groups (r=-0.948, -0.602, and -0.735, all P＜0.01). In the compensated liver cirrhosis group and decompensated liver cirrhosis group, HBsAg was positively correlated with PTA (r=0.410 and 0.473, both P＜0.05) and negatively correlated with ICG R15 (r=-0.427 and -0.768, P＜0.01). ConclusionIn HBeAg positive patients, there are certain correlations between HBsAg, PTA, and ICG R15, which, to a certain degree, reflects the liver reserve function in patients with chronic HBV infection

Effects of steaming treatment on crystallinity and glass transition temperature of Eucalyptuses grandis × E. urophylla

To investigate the effects of steaming treatment on crystallinity and glass transition temperature, samples of Eucalyptuses grandis × E. urophylla with moisture content of 50%, 70%, and 90% were steamed in saturated steam at 100 °C for 2, 4, 6, and 8 h. The degree of crystallinity (CrI) and glass transition temperature (Tg) were measured via X-ray diffraction and dynamic mechanical analysis, respectively. Results revealed a crystallinity degree of Eucalyptus of 29.9%–34.2%, and a glass transition temperature of 80–94 °C with moisture contents of steamed samples of 20%. Furthermore, steaming was revealed to have an obvious effect on crystallization and glass transition. Values of CrI and Tg showed similar changing characteristics: increasing initially, followed by a decrease with increasing steaming time, reaching a maximum at 2 h. Water within the wood seemed to promote crystallization and glass transition during steaming. All steamed samples tested in this study reached glass transition temperature after 50 min of steaming, and the residual growth stress was released. Keywords: Eucalyptuses grandis × E. urophylla, Steaming, Moisture content, Crystallinity, Glass transition temperatur

Effect of ultrasound pretreatment on wood prior to vacuum drying

The influence of ultrasonic pretreatment prior to vacuum drying of Chinese fir specimens was examined in this work. In the pretreatments, wood samples were immerged in a distilled water bath and were treated using two wave frequencies for four different elapsed times to investigate effects of ultrasonic frequency and treatment duration. Then the wood samples were vacuum-dried at 80°C and absolute pressure of 0,05 MPa. After the pretreatment, microscopic analysis was carried out on the wood samples to check micro-cracks, the loss of extractives from the cell walls and other micro-structural changes on the wood. Results show that the ultrasonic treatment prior to vacuum drying significantly shortened the wood drying time. The drying time decreased with increase in the wave frequency and the treatment time. Furthermore, ultrasound pretreatment tended to reduce the content of extractives in the wood cell walls and cause cell-wall micro- cracking

Effects of Frequency and Processing Time on the Drying Course of Ultrasound-assisted Impregnated Wood

Impregnating wood, assisted with ultrasound technology, could improve the impregnation efficiency by improving the permeability of wood, thus affecting the subsequent drying process. Poplar lumber and phenolic resin were applied to investigate the influence of ultrasound-assisted impregnation on the wood drying process. The ultrasonic frequency and processing time were analyzed and correlated. The results indicated that the average drying rate of impregnated wood was generally faster in the earlier stage and slower in the later period than the blank group. At the earlier drying stage, the drying rate exhibited a decreasing tendency with increasing ultrasonic time, as the frequency remained constant. However, with an unaltered processing time, a contrary trend was detected as the frequency was increased. The ultrasonic frequency and time caused an complex effect on the average drying rate during the later drying course. These findings could be applied to the impregnated wood drying industry to strike a balance between ultrasound-assisted performance and the related drying effectiveness

Numerical simulation for resistance of trimaran small waterplane area center hull based on STAR-CCM+

[Objectives] Due to its excellent seakeeping, rapidity and stability, Trimaran Small Waterplane Area Center Hull(TriSWACH)has an increasing number of applications in both civil vessels and warships. However, the laws of resistance of different submerged body shapes and side-hull configurations at different speeds still require research. As model tests are time-consuming and expensive, and cannot cover all potential hulls, numerical calculation based on STAR-CCM + is becoming increasingly preferred.[Methods] With the free surface effect consideration,STAR-CCM+ is validated to be practical for TriSWACH resistance prediction. The resistance performance is calculated with different side-hull configurations,including longitudinal and transverse,of circular submerged body shapes under the Fr series.[Results] As the results indicate,with the increase of speed,when the side-hull is arranged behind and moves closer to the main hull,the total resistance of TriSWACH is significantly lower than that of traditional trimarans,in the range of Fr=0.338~0.494.[Conclusions] The findings in this paper can provide useful references for future TriSWACH design