Adjoints estimation methods for impulsive Moon‐to‐Earth trajectories in the restricted three‐body problem

A study of optimal impulsive Moon‐to‐Earth trajectories is presented in a planar circular restricted three‐body framework. Two‐dimensional return trajectories from circular lunar orbits are considered, and the optimization criterion is the total velocity change. The optimal conditions are provided by the optimal control theory. The boundary value problem that arises from the application of the theory of optimal control is solved using a procedure based on Newton's method. Motivated by the difficulty of obtaining convergence, the search for the initial adjoints is carried out by means of two different techniques: homotopic approach and adjoint control transformation. Numerical results demonstrate that both initial adjoints estimation methods are effective and efficient to find the optimal solution and allow exploring the fundamental tradeoff between the time of flight and required ΔV. Copyright © 2014 John Wiley & Sons, Ltd.     

Cross‐sex hormone therapy in transgender persons affects total body weight,body fat and lean body mass: a meta‐analysis

Weight gain and body fat increase the risk of cardiometabolic disease. Cross‐sex hormone therapy in transgender persons leads to changes in body weight and body composition, but it is unclear to what extent. We performed a meta‐analysis to investigate the changes in body weight, body fat and lean body mass during cross‐sex hormone therapy in transgender persons. We searched the PubMed database for eligible studies until November 2015. Ten studies reporting changes in body weight, body fat or lean mass in hormone naive transgender persons were included, examining 171 male‐to‐female and 354 female‐to‐male transgender people. Pooled effect estimates in the male‐to‐female group were +1.8 kg (95% CI: 0.2;3.4) for body weight, +3.0 kg (2.0;3.9) for body fat and ?2.4 kg (?2.8; ?2.1) for lean body mass. In the female‐to‐male group, body weight changed with +1.7 kg (0.7;2.7), body fat with ?2.6 kg (?3.9; ?1.4) and lean body mass with +3.9 kg (3.2;4.5). Cross‐sex hormone therapy increases body weight in both sexes. In the male‐to‐female group, a gain in body fat and a decline in lean body mass are observed, while the opposite effects are seen in the female‐to‐male group. Possibly, these changes increase the risk of cardiometabolic disease in the male‐to‐female group.     

Distinct frequency dependent effects of whole‐body vibration on non‐fractured bone and fracture healing in mice

Low‐magnitude high‐frequency vibration (LMHFV) provokes anabolic effects in non‐fractured bone; however, in fracture healing, inconsistent results were reported and optimum vibration conditions remain unidentified. Here, we investigated frequency dependent effects of LMHFV on fracture healing. Twelve‐week‐old, female C57BL/6 mice received a femur osteotomy stabilized using an external fixator. The mice received whole‐body vibrations (20 min/day) with 0.3g peak‐to‐peak acceleration and a frequency of either 35 or 45 Hz. After 10 and 21 days, the osteotomized femurs and intact bones (contra‐lateral femurs, lumbar spine) were evaluated using bending‐testing, µ‐computed tomography, and histomorphometry. In non‐fractured trabecular bone, vibration with 35 Hz significantly increased the relative amount of bone (+28%) and the trabecular number (+29%), whereas cortical bone was not influenced. LMHFV with 45 Hz failed to provoke anabolic effects in trabecular or cortical bone. Fracture healing was not significantly influenced by whole‐body vibration with 35 Hz, whereas 45 Hz significantly reduced bone formation (?64%) and flexural rigidity (?34%) of the callus. Although the exact mechanisms remain open, our results suggest that small vibration setting changes could considerably influence LMHFV effects on bone formation in remodeling and repair, and even disrupt fracture healing, implicating caution when treating patients with impaired fracture healing. © 2014 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:1006–1013, 2014.

     

Excellent Clinical Outcomes From a National Donation‐After‐Determination‐of‐Cardiac‐Death Lung Transplant Collaborative

Donation‐after‐Determination‐of‐Cardiac‐Death (DDCD) donor lungs can potentially increase the pool of lungs available for Lung Transplantation (LTx). This paper presents the 5‐year results for Maastricht category III DDCD LTx undertaken by the multicenter Australian National DDCD LTx Collaborative. The Collaborative was developed to facilitate interaction with the Australian Organ Donation Authority, standardization of definitions, guidelines, education and audit processes. Between 2006 and 2011 there were 174 actual DDCD category III donors (with an additional 37 potentially suitable donors who did not arrest in the mandated 90 min postwithdrawal window), of whom 71 donated lungs for 70 bilateral LTx and two single LTx. In 2010 this equated to an “extra” 28% of donors utilized for LTx. Withdrawal to pulmonary arterial flush was a mean of 35.2 ± 4.0 min (range 18–89). At 24 h, the incidence of grade 3 primary graft dysfunction was 8.5%[median PaO₂/FiO₂ ratio 315 (range 50–507)]. Overall the incidence of grade 3 chronic rejections was 5%. One‐ and 5‐year actuarial survival was 97% and 90%, versus 90% and 61%, respectively, for 503 contemporaneous brain‐dead donor lung transplants. Category III DDCD LTx therefore provides a significant, practical, additional quality source of transplantable lungs.     

Non‐invasive fat reduction of the flanks using a new cryolipolysis applicator and overlapping,two‐cycle treatments

Background and Objectives

A sharply contoured cryolipolysis vacuum applicator was developed to improve fit and tissue draw in the abdomen and flanks to better accommodate a range of body types and a variety of treatment sites. This study was carried out to evaluate the safety and efficacy of the new applicator for treatment of flank fat (“love handles”).

Study Design/Materials and Methods

A cryolipolysis vacuum applicator with a sharply contoured cup and curved cooling plates was used to treat 20 flanks. Two treatment cycles were delivered sequentially to each flank (60‐minute cycle at a Cooling Intensity Factor of 41.6). Efficacy was evaluated 12 weeks post‐treatment by physicians performing blinded, independent review of clinical photographs. Safety was assessed by the treating physician monitoring subjects for side effects and adverse events.

Results

Four blinded, independent physician reviewers properly identified the pre‐ and post‐treatment photographs 94.4% of the time. Improvement was scored from 0 (none) to 10 (complete) and showed an average 4.3 point (43%) improvement. Side‐effects were limited to erythema, edema, bruising, and numbness or tingling at the treatment site, and resolved without treatment.

Conclusions

Multiple treatment cycles from a new improved‐fit cryolipolysis applicator are safe and effective for reduction of flank fat bulges. A high degree of improvement was reported by blinded, physician evaluation of standardized photographs. Laser Surg. Med. 46:731–735, 2014. © 2014 The Authors. Lasers in Surgery and Medicine published by Wiley Periodicals, Inc.     

Effect of ageing and body mass index on prostate‐specific antigen levels among Chinese men in Singapore from a community‐based study

OBJECTIVE

To assess the effect of ageing and body mass index (BMI) on prostate‐specific antigen (PSA) among Chinese men from the results of the 2005 Prostate Awareness Week in Singapore.

SUBJECTS AND METHODS

In all, 2714 men participated in the programme, consisting of 2431 Chinese, 114 Malays, 117 Indians and 52 ‘others’. Of these, 2410 Chinese men who had a PSA level of <20 ng/mL and were aged >50 years but <80 years were included in the analysis. Height and weight were used to calculate the BMI. The relationship between age and PSA levels was analysed using linear regression and bivariate correlation, and the associations among different groups of BMI and PSA levels were analysed using analysis of variance and covariance.

RESULTS

PSA levels were significantly correlated with age (correlation coefficient, r = 0.27, P < 0.001). Analyses showed a significant inverse association between PSA level and BMI; mean PSA levels decreased with increasing BMI for both standards (standard classification; geometric mean, GM, PSA of 1.08, 1.06, 0.96, 0.83 ng/mL for a BMI of <18.5, 18.5–24.9, 25–29.9 and ≥30 kg/m², respectively, P trend <0.01; and for Asian classification, GM PSA 1.08, 1.09, 0.96, 0.91 ng/mL for a BMI of <18.5, 18.5–22.9, 23–27.5 and ≥27.5, respectively, P trend <0.001). There were significant differences (P < 0.05) in the age‐adjusted GM PSA levels for the groups with BMI <25 (1.05 ng/mL) and BMI ≥25 kg/m² (0.97 ng/mL). Similarly, there were significant differences (P < 0.05) in the age‐adjusted GM PSA levels in those with a BMI of <30 (1.03 ng/mL) and ≥30 kg/m² (0.85 ng/mL).

CONCLUSION

These data suggest that the BMI in Chinese men in Singapore is significantly associated with PSA levels, especially among the obese men aged 70–79 years.     

Low‐magnitude whole‐body vibration does not enhance the anabolic skeletal effects of intermittent PTH in adult mice

Whole‐body vibration (WBV) is a low‐magnitude mechanical stimulus that may be anabolic for bone, yet we recently found that WBV did not improve bone properties in adult mice. Because intermittent parathyroid hormone (PTH) enhances the anabolic effects of high‐magnitude skeletal loading, we sought to determine the skeletal effects of WBV in combination with PTH. Seven‐month‐old male BALB/c mice were assigned to six groups (n = 13–14/group) based on magnitude of applied acceleration (0 or 0.3 G) and PTH dose (0, 10, or 40 µg/kg/day). Mice were exposed to WBV (0.3 G, 90 Hz, sine wave) or sham loading (0 G) for 15 min/day, 5 days/week for 8 weeks. Vehicle or hPTH (1–34) was administered prior to each WBV session. Whole‐body bone mineral content increased by ～5% from 0 to 8 weeks in the 40 µg/kg PTH group only, independent of WBV loading. Similarly, PTH treatment increased tibial cortical bone volume by ～5% from 0 to 8 weeks, independent of WBV loading. Neither PTH nor WBV stimulated trabecular bone formation. Consistent with the cortical bone effect, tibias from the 40 µg/kg PTH group had significantly greater ultimate force and energy to failure than tibias in the 0 and 10 µg/kg PTH groups, independent of WBV treatment. In summary, 8 weeks of intermittent PTH treatment increased cortical bone volume and strength in adult male BALB/c mice. Daily exposure to low‐magnitude WBV by itself did not improve skeletal properties and did not enhance the PTH effect. No WBV‐PTH synergy was found in this preclinical study. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:465–472, 2011     

Effect of component mal‐rotation on knee loading in total knee arthroplasty using multi‐body dynamics modeling under a simulated walking gait

Mal‐rotation of the components in total knee arthorplasty (TKA) is a major cause of postoperative complications, with an increased propensity for implant loosening or wear leading to revision. A musculoskeletal multi‐body dynamics model was used to perform a parametric study of the effects of the rotational mal‐alignments in TKA on the knee loading under a simulated walking gait. The knee contact forces were found to be more sensitive to variations in the varus–valgus rotation of both the tibial and the femoral components and the internal–external rotation of the femoral component in TKA. The varus–valgus mal‐rotation of the tibial or femoral component and the internal–external mal‐rotation of the femoral component with a 5° variation were found to affect the peak medial contact force by 17.8–53.1%, the peak lateral contact force by 35.0–88.4% and the peak total contact force by 5.2–18.7%. Our findings support the clinical observations that a greater than 3° internal mal‐rotation of the femoral component may lead to unsatisfactory pain levels and a greater than 3° varus mal‐rotation of the tibial component may lead to medial bone collapse. These findings determined the quantitative effects of the mal‐rotation of the components in TKA on the contact load. The effect of such mal‐rotation of the components of TKA on the kinematics would be further addressed in future studies. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1287–1296, 2015.     

Comparative analysis on the effect of low‐thermal plasma dissection device (PEAK PlasmaBlade) versus conventional electro surgery in post‐bariatric body‐contouring procedures: A retrospective randomised clinical study

Postoperative wound‐healing problems are relatively high in post‐bariatric body‐contouring procedures, partly because of electrosurgery and the associated thermal tissue damage. This study is a retrospective randomised evaluation of the effect of a low‐thermal plasma dissection device (PEAK PlasmaBlade, Medtronic, Minneapolis, Minnesota) in comparison with conventional electrosurgery. A total of 24 patients undergoing upper arm or medial thigh lifting were randomised to PEAK PlasmaBlade on one side and to monopolar electrosurgery on the other side of the same patient. Wounds of 10 patients were examined histologically for acute thermal injury depth. Significantly lower total volume of drain output (61,1 ± 70,2 mL versus 95,1 ± 176,0 mL; P = .04) was found on the PEAK PlasmaBlade side compared with the electrosurgery side. Furthermore, the PEAK PlasmaBlade side showed fewer seromas (no case of seroma versus three seromas in the electrosurgery group) and less thermal damage (40% versus 70%; P = .26). Acute thermal injury depth from the PEAK PlasmaBlade was less than from monopolar electrosurgery (425 ± 171 μm versus 686 ± 1037 μm; P = .631). PEAK PlasmaBlade appears to be superior to traditional monopolar electrosurgery for post‐bariatric body‐contouring procedures because it demonstrated less tissue damage, lower total volume of drain output, and fewer postoperative seromas resulting in faster wound healing.     

Evaluation of Hyphecan (1‐4,2‐acetamide‐deoxy‐B‐D‐glucan polymer) on wound healing in a rodent model

Objective: To evaluate the effect of an artificial skin Hyphecan (1‐4,2‐acetamide‐deoxy‐B ‐D ‐glucan polymer) on wound healing in a rodent model. Materials and Method: The prospective study was conducted at a basic science laboratory at a tertiary teaching hospital. Two 4 cm × 4 cm full‐thickness wounds were created on the dorsal surface of 10 Spraque–Dawley rats and covered with Hyphecan and Kaltostat, respectively. Wounds were examined and measured on days 4, 10, 21 and 28, and would continue after day 28 until healed up completely. Punch biopsies (3 mm) were taken on days 4, 10 and 28 for histological examination of the response of healing and repair. Results: Despite the fact that the wound healing rate was similar for both groups on days 4, 10, 21 and 28, the average healing time for the Hyphecan group (29.1 ± 1.7 days) was significantly shorter statistically (P = 0.03) than the Kaltostat group (30.7 ± 2.8 days). Conversely, the marked healing response elicited by Hyphecan on day 4 persisted on days 10 and 28 in contrast to Kaltostat, which had only a mild degree of healing response on days 10 and 28. The study suggests that wounds treated by Hyphecan heal faster than Kaltostat. Conclusion: The findings provide basic scientific evidence supporting the clinical use of Hyphecan in different wounds and might also reduce the cost of wound management as Hyphecan is cheaper than Kaltostat and requires a shorter treatment time.