Mechanical measurement of the human cerebellum under compressive loading

The cerebellum is responsible for controlling the posture and walking stability of the body. The cerebellum can subject to the traumatic injuries following by complicated clinical problems, i.e., the cerebellar pathologies. Application of the computational models can be helpful to figure out the injury mechanisms of the cerebellum, however, there is a lack of knowledge on the mechanical properties of the cerebellum under compressive loading. Therefore, this study aimed to perform an experimental study to measure the mechanical properties of 17 male individuals’ cerebellum under the series of compressive loadings. The resulted stress-strain data of the cerebellum revealed the elastic modulus and maximum/failure stress of 13.48?±?2.65 (Mean?±?SD) and 19.65?±?3.89?kPa, respectively. The findings of this study have implications not only for understanding the mechanical properties of the human cerebellum tissue under the compressive loading, but also for providing a raw data for the doctors and biomechanical experts as the mechanical threshold of the cerebellum as well as computational modelling of the traumatic brain injuries.     

Evaluation of a novel permanent capped helical coil fastener in a porcine model of laparoscopic ventral hernia repair

Background

Existing permanent helical coil fasteners, although commonly employed for mesh fixation during laparoscopic hernia repair, are associated with peritoneal tissue attachment formation and resultant visceral complications. We evaluated attachment formation, fastener engagement, and mesh/tissue integration associated with laparoscopic fixation using a novel permanent capped helical coil fastener (HC-Capped) compared to permanent non-capped helical coil fasteners (HC-Non-Capped) in a porcine model.

Methods

Twelve female pigs underwent bilateral laparoscopic intraperitoneal fixation of Composix? L/P Mesh (10 × 15 cm oval) with HC-Capped or HC-Non-Capped fasteners. Thirty-two fasteners were used to secure each mesh utilizing a “double-crown” technique. Laparoscopy at 30 days was used to evaluate the presence and area coverage of attachments (Diamond Score) and percentage of engaged fasteners. At 90 days, following necropsy, each mesh was evaluated for the presence, percentage, and tenacity (Butler Score) of attachments and fastener engagement. Samples were biomechanically evaluated to assess tissue integration via T-peel testing.

Results

HC-Capped fasteners demonstrated a significantly lower attachment area score compared to the HC-Non-Capped group at 30 days (0.92 ± 0.26 vs. 2.50 ± 0.29/3.00, p = 0.002) and 90 days (0.60 ± 0.22 vs. 2.08 ± 0.29/3.00, p = 0.004). At 90 days, the HC-Capped group evidenced significantly lower attachment tenacity score (1.00 ± 0.37 vs. 2.75 ± 0.33/4.00, p = 0.013). Furthermore, at 30 and 90 days, a significantly greater percentage of HC-Capped fasteners remained properly engaged (30 days: 99.7 % vs. 86.5 %, p < 0.001 and 90 days: 99.4 % vs. 74.5 %, p = 0.001). T-peel biomechanical testing demonstrated significantly greater mesh/tissue integration for HC-Capped group (2.16 ± 0.24 vs. 1.16 ± 0.29 N/cm, p = 0.038).

Conclusions

In a porcine model, HC-Capped fasteners demonstrated significantly less attachment coverage and tenacity in the early postoperative period. Furthermore, the HC-Capped cohort evidenced significantly greater percentage of properly engaged fasteners and greater mesh/tissue integration. Data suggest that shielding exposed fastener points on the visceral mesh surface with polymer caps may reduce attachment formation and aid in mesh fixation and integration.

     

Comparative evaluation of the effects of tranexamic acid and low-dose aprotinin on post-valvular heart surgery bleeding and allogenic transfusion

Bleeding diathesis and allogenic transfusion after complex heart surgery, such as heart valve surgery, may result in complications such as transfusion reaction, viral infection, postoperative infection, haemodynamic disturbance, prolonged stay in the intensive care unit and hospital, renal and respiratory failure and mortality. In this prospective, double-blind, randomized, placebo-controlled clinical trial, 90 patients were randomly divided into three groups: aprotinin, tranexamic acid and control. Chest-tube drainage, transfusion requirements and renal and neurological complications were evaluated. We found that chest-tube drainage during the first (P < 0.0001) and second 24 h (P = 0.001) after admission to the intensive care unit were significantly lower in the aprotinin group. The amounts of transfused packed red blood cells (P < 0.0001) and platelets (P = 0.02) were significantly lower in the aprotinin and tranexamic acid groups. The quantity of transfused fresh frozen plasma (P = 0.034) was significantly lower in the aprotinin group only. We did not find any neurological complications or renal failure in the three groups. Our data suggest that in valvular heart surgery, low-dose aprotinin is significantly better than tranexamic acid or a placebo for reduction of postoperative bleeding and allogenic transfusion, without increasing adverse outcomes.     

Effect of nature-based sound therapy on agitation and anxiety in coronary artery bypass graft patients during the weaning of mechanical ventilation: A randomised clinical trial

Background

Weaning from mechanical ventilation is a frequent nursing activity in critical care. Nature-based sound as a non-pharmacological and nursing intervention effective in other contexts may be an efficient approach to alleviating anxiety, agitation and adverse effects of sedative medication in patients undergoing weaning from mechanical ventilation.

Objectives

This study identified the effect of nature-based sound therapy on agitation and anxiety on coronary artery bypass graft patients during weaning from mechanical ventilation.

Methods

A randomised clinical trial design was used. 120 coronary artery bypass graft patients aged 45–65 years undergoing weaning from mechanical ventilation were randomly assigned to intervention and control groups. Patients in the intervention group listened to nature-based sounds through headphones; the control group had headphones with no sound. Haemodynamic variables, anxiety levels and agitation were assessed using the Faces Anxiety Scale and Richmond Agitation Sedation Scale, respectively. Patients in both groups had vital signs recorded after the first trigger, at 20 min intervals throughout the procedure, immediately after the procedure, 20 min after extubation, and 30 min after extubation. Data were collected over 5 months from December 2012 to April 2013.

Results

The intervention group had significantly lower anxiety and agitation levels than the control group. Regarding haemodynamic variables, a significant time trend and interaction was reported between time and group (p < 0.001). A significant difference was also found between the anxiety (p < 0.002) and agitation (p < 0.001) scores in two groups.

Conclusions

Nature-based sound can provide an effective method of decreasing potential adverse haemodynamic responses arising from anxiety and agitation in weaning from mechanical ventilation in coronary artery bypass graft patients. Nurses can incorporate this intervention as a non-pharmacological intervention into the daily care of patients undergoing weaning from mechanical ventilation in order to reduce their anxiety and agitation.     

Experiences of infertility through the lens of Iranian infertile women: A qualitative study

Aim: The purpose of this study was to explore and describe the experiences of Iranian infertile women regarding infertility. Methods: A qualitative design, based on a content analysis approach, was used to reach this study aim. After employing purposive sampling to choose 10 women who were seeking infertility treatment at a referral center in Tehran, Iran, semi‐structured interviews were carried out to gather data. Results: During the data analysis, four main themes emerged including “abuse”, “marital instability”, “social isolation”, and “loss of self‐ esteem”. Conclusion: Infertility influences both the psychological and social well‐being of women. Improving the knowledge of healthcare professionals especially nurses about the complications of infertility and its related cultural–contextual factors are crucial in order to provide high quality care to infertile women.     

Psychometric properties of the Iranian version of the Kogan's Attitudes Toward Older People Scale

Aim: The purpose of this study was to assess the psychometric properties “validity” and “reliability” of the Iranian version of Kogan's Attitudes Toward Older People Scale (KAOPS). Methods: The participants consisted of 350 nurses working in five teaching hospitals in Tehran, Iran. The scale was translated using the forward–backward translation technique. A two‐phase data collection design was used in 2 weeks following the first completion. Exploratory factor analysis, content validity, construct validity, internal consistency, and stability–reliability was employed to check the scale's psychometric properties. Results: The scale total scores were between 42 and 188. All of the 34 items were found to have significant item‐to‐total correlations (P < 0.05). Two factors were extracted –“prejudice' and “appreciation”– which contributed to the scale variance of 32.83% and 25.93%, respectively. Cronbach's alpha was 0.83 for the total scale as 0.83 for “prejudice” and 0.86 for “appreciation”. In addition, the scale stability was reported to be 0.90 and 0.83 for “prejudice” and “appreciation”, respectively. The average content validity was 0.95, and construct validity was in an acceptable range. Conclusion: The Iranian version of the KAOPS was shown to be a valid and reliable instrument for measuring nurses' knowledge about elders. This scale can be used in future studies to gather high‐quality data for improving elder care.     

Ovarian activity in high and average producing Holstein cows under heat stress conditions

The aim of the present study was to investigate the ovarian activity in high and average producing Holstein cows under heat stress conditions (temperature–humidity index [THI]=81.5 ± 3.9). Cows were kept in free-stall barns and fed a total mixed ration consisting mainly of alfalfa, corn silage, beet pulp, cotton seed, soybean, corn and barley. Forty high producing (HP, mean 305-day fat-corrected milk [FCM] = 8707.3 kg) and 30 average producing (AP, FCM = 6115.1 kg) multiparous healthy (free of detectable reproductive disorders) Holstein cows were monitored from 14 days before to 70 days after calving. Transrectal ultrasound scanning was performed twice weekly from 7 to 65 days postpartum. Blood samples were also collected twice weekly to measure serum progesterone and biweekly to detect serum β-hydroxybutyrate (βHB) and non-esterified fatty acid (NEFA) concentrations. Body condition score (BCS) was taken biweekly after calving. Cows were observed visually four times a day to determine the duration of standing estruses. Classification of the serum progesterone profiles revealed a non-significant difference between HP and AP cows with abnormal ovarian activity (63.6% [21/33] and 46.2% [12/26], respectively, p > 0.05). The highest type of abnormal ovarian activity was delayed first postpartum ovulation 36.4% (12/33) in HP and 38.5% (10/26) in AP cows (p > 0.05). The lowest type of abnormality was the cessation of ovarian activity in HP and AP cows, 3.0% (1/33) vs 3.8% (1/26), respectively. The mean concentrations of both metabolites in HP cows were greater than AP cows at any time after calving (NEFA and βHB [p > 0.05]). There was significant difference in estrous duration between groups ([mean±SD] 6.1 ± 2.7 h in HP and 10.5 ± 2.9 h in AP cows, P < 0.05). The loss of body condition score (BCS loss >0.5) significantly affected calving to first detected estrus interval in HP cows (P < 0.05), whereas calving to first detected estrus interval was not significantly affected in AP cows. The most important abnormality of ovarian activity was delayed first ovulation in high and average producing dairy cows under heat stress conditions.     

Preparation and investigation the release behaviour of wax microspheres loaded with salicylic acid

Salicylic acid-beeswax microspheres were prepared by melt dispersion technique. The effects of formulation parameters on the microscopic characteristic, drug loading and cumulative amount of released drug were investigated by experimental design. Results showed that all of the microparticles were spherical with porous surfaces. The average size of microspheres was 24-48 microm, the drug content was in the range of 22-45% and the encapsulation efficiency was 46-93%. Drug loading was influenced by emulsification speed as a main factor. All the microspheres had a burst release initially. The emulsifier concentration did not have a significant effect on drug release. The release behaviour of microspheres conformed best to Korsmeyer-Peppas semi-empirical model and the release of SA from beeswax microspheres was Fickian (n < 0.45).