Smearing model and restoration of star image under conditions of variable angular velocity and long exposure time.

The star tracker is one of the most promising attitude measurement devices widely used in spacecraft for its high accuracy. High dynamic performance is becoming its major restriction, and requires immediate focus and promotion. A star image restoration approach based on the motion degradation model of variable angular velocity is proposed in this paper. This method can overcome the problem of energy dispersion and signal to noise ratio (SNR) decrease resulting from the smearing of the star spot, thus preventing failed extraction and decreased star centroid accuracy. Simulations and laboratory experiments are conducted to verify the proposed methods. The restoration results demonstrate that the described method can recover the star spot from a long motion trail to the shape of Gaussian distribution under the conditions of variable angular velocity and long exposure time. The energy of the star spot can be concentrated to ensure high SNR and high position accuracy. These features are crucial to the subsequent star extraction and the whole performance of the star tracker.

Super-thin anterolateral thigh flap for reconstruction of the medial plantar artery perforator flap donor site.

BACKGROUND: The medial plantar artery perforator (MPAP) flap is widely used to reconstruct the weight-bearing area of the foot. Traditionally, its donor site is closed using a skin graft, which is associated with several complications, including walking disability. This study aimed to examine our experience with using a super-thin anterolateral thigh (ALT) flap to reconstruct the MPAP flap donor site. METHODS: We examined 10 patients who underwent reconstruction of the MPAP flap donor site using a super-thin ALT flap between August 2019 and March 2021. The vascular pedicle was anastomosed to the proximal end of the medial plantar vessels or the end of the posterior tibial vessels. RESULTS: All reconstruction flaps survived and all patients were satisfied with the aesthetic appearance. No blisters, ulcerations, hyperpigmentation, or contractures occurred. All patients gained protective sensation in the super-thin ALT flap. The average visual analog scale score for the aesthetic appearance of the reconstructed foot was 8.5 ± 0.7 (range, 8-10). All patients were able to ambulate without aids and could wear regular shoes. The average revised Foot Function Index score was 26.4 ± 4.1 (range, 22-34). CONCLUSION: Reconstruction of the MPAP flap donor site using a super-thin ALT flap is reliable and provides satisfactory functional recovery, aesthetic appearance, and protective sensation while minimizing postoperative morbidity.

Hook plate fixation with versus without coracoclavicular reconstruction for distal clavicular fractures.

PURPOSE: Hook plate fixation is one of the most frequently used methods for unstable distal clavicular fractures, but it is still unknown if there is a need for coracoclavicular (CC) reconstruction. This study aimed to compare the efficacy of hook plate fixation with versus without CC reconstruction for distal clavicular fractures. METHODS: Eighty-one patients who underwent hook plate fixation (HP group, n = 45) or hook plate fixation plus suture anchor reconstruction (HPA group, n = 36) for Neer type II or V clavicular fractures were enrolled. Demographics, fracture characteristics, and surgical data were recorded. Union time, coracoclavicular distance (CCD), post-operative complications, Constant score, and Disabilities of the Arm, Shoulder, and Hand (DASH) score were compared between HPA and HP groups. RESULTS: Constant score in the HPA group was higher than that in the HP group (91.8 ± 3.6 vs 88.8 ± 6.0, P = 0.007). However, there were no significant differences in union time, DASH score, CCD, and post-operative complications between the two groups (P > 0.05). Hook plate fixation combined with CC reconstruction costed more (3023.7 ± 202.6 vs 2416.2 ± 167.6 EUR, P < 0.001) and prolonged operative duration (78.2 ± 9.2 vs 73.7 ± 8.3 min, P = 0.023) compared with hook plate fixation alone. CONCLUSION: Hook plate fixation with or without suture anchor reconstruction achieved satisfactory outcomes for Neer type II or V clavicular fractures. However, hook plate fixation plus CC reconstruction showed better functional outcomes compared with hook plate fixation alone.

[Research progress in treatment of proximal humeral fracture with fibular allograft and locking plate].

OBJECTIVE: To review the research progress in the treatment of proximal humeral fractures with fibular allograft and locking plate. METHODS: The literature about the treatment of proximal humeral fractures with fibular allograft and locking plate was reviewed and analyzed from the aspects such as the biomechanics, imaging prognosis, and clinical prognosis. RESULTS: Fibular allograft and locking plate can provide effective medial support for proximal humeral fracture and increase the strength of internal fixation system. Compared with locking plate, fibular allograft combined with locking plate can maintain better humeral neck-shaft angle and the humeral head height after operation in the treatment of proximal humeral fractures, and has better shoulder mobility and shoulder joint function, and does not increase the risk of complications. CONCLUSION: Fibular allograft combined with locking plate may be a new and effective treatment for proximal humeral fractures. However, the long-term follow-up results are insufficient, the final outcome of fibula is uncertain, and the long-term potential adverse reactions caused by this treatment are still indefinite.

Postoperative outcomes of tranexamic acid use in geriatric trauma patients treated with proximal femoral intramedullary nails: A systematic review and meta-analysis.

BACKGROUND: Recently, there has been a series of clinical studies focusing on the perioperative administration of tranexamic acid (TXA) in geriatric trauma patients undergoing proximal femoral intramedullary nail surgery. However, the safety and efficacy of TXA in these patients remains controversial. Therefore, we performed a systematic review to focus on two questions: (1) would TXA reduce perioperative blood loss in geriatric trauma patients undergoing proximal femoral intramedullary nail surgery? and (2) would TXA increase the rate of perioperative complications in geriatric trauma patients undergoing proximal femoral intramedullary nail surgery? PATIENTS AND METHODS: We systematically searched electronic databases (MEDLINE, EMBASE, PubMed, and Cochrane Central Register of Controlled Trials) up to April 20, 2019. The perioperative blood loss and complication data were extracted and analysed by RevMan Manager 5.3. RESULTS: Finally, five randomized controlled studies, involving 539 geriatric intertrochanteric fracture patients undergoing proximal femoral intramedullary nail surgery, were enrolled in this systematic review. Compared with the control group, the TXA group had significantly lower total perioperative blood loss (WMD=-172.84; 95% CI, -241.44 to -104.24; I2=0%), intraoperative blood loss (WMD=-34.20; 95% CI, -46.04 to -22.36; I2=0%), total perioperative hidden blood loss (WMD=-139.05; 95% CI, -213.67 to -64.43; I2=0%), perioperative transfusion rates (RR =-0.16; 95% CI, -0.24 to -0.08; I2=22%), length of hospital stay (WMD=-1.18; 95% CI, -1.91 to -0.46; p=0.001; I2=12%), and postoperative wound haematoma rates (RD=-0.05; 95% CI, -0.09 to 0.00; p=0.03; I2=0%). In addition, there were no significant differences between TXA and control groups in the terms of surgical time, postoperative mortality, total thromboembolic events, wound infections, cerebrovascular accidents, respiratory infections, and renal failure. DISCUSSION: TXA in geriatric trauma patients undergoing intramedullary nail surgery is effective for perioperative haemostasis without increasing the incidence of postoperative complications. LEVEL OF EVIDENCE: II, Systematic review and Meta-analysis.

The protective effects of gonadotropin-releasing hormone agonist on ovarian functions in breast Cancer patients receiving chemotherapy.

In recent decades, the incidence rate of breast cancer has increased dramatically worldwide and has become one of the most prevalent cancers in women. According to the global data provided by the WHO, there were more than 1.7 million new cases of breast cancer in 2012, accounting for 25% of all reported cancer cases and 15% of all reported deaths among females. To most young patients, especially those younger than 40 years of age, chemotherapy should be taken into consideration as a treatment modality, even if the tumor size is small or without lymphatic metastasis. A significant portion of the patients will suffer from the side effects that result from long-term chemotherapy regimens, such as myelosuppression, heart failure, and development of a second primary malignancy. Ovarian suppression and premature ovarian failure (POF) are the most common side effects reported as they have notable clinical symptoms; the incidence rates have been reported to be in a range of 10-90%. Gonadotropin-releasing hormone agonists (GnRH-a), also termed luteinizing hormone release hormone agonists (LHRH-a), may very well offer a solution to treating these side effects. This article aims to summarize advanced studies concerning protective effects of GnRH-a on ovarian functions in the setting of breast cancer under chemotherapy.

Sliding hip screw versus cannulated cancellous screws for fixation of femoral neck fracture in adults: A systematic review.

OBJECTIVE: Femoral neck fracture is considered a difficult fracture to treat and often gives rise to unsatisfactory treatment results. Cannulated cancellous screws (CCS) or a sliding hip screw (SHS) are the mainstream internal fixations used for osteosynthesis of femoral neck fractures. There is a need to integrate existing data through a meta-analysis to investigate the safety and effectiveness of CCS and SHS in the treatment of femoral neck fractures. METHOD: According to the Cochrane Handbook for Systematic Reviews of Interventions, we screened for the relevant studies by searching Google Scholar, the Cochrane Controlled Trials Register, the Cochrane Library, Web of Science, EMBASE, and PubMed. The PICOS criteria was used to make sure the included studies fulfilled the inclusion criteria. RESULTS: Pooled data showed that there were no significant differences between the SHS and CCS groups for the Harris Hip Score. Significant differences were found between the SHS and CCS groups in terms of union time, postoperative complications, blood loss, operation time, incision length and length of hospital stay. CONCLUSIONS: Although the SHS and CCS groups showed similar functional recovery in treatment of femoral neck fracture in terms of the Harris Hip Score, the SHS group showed fewer postoperative complications and faster union time for patients with femoral neck fractures. Therefore, compared with CCS, the use of SHS may be a more effective treatment of femoral neck fractures.