Aspect-Aware Target Detection and Localization by Wireless Sensor Networks.

This paper considers the active detection of a stealth target with aspect dependent reflection (e.g., submarine, aircraft, etc.) using wireless sensor networks (WSNs). When the target is detected, its localization is also of interest. Due to stringent bandwidth and energy constraints, sensor observations are quantized into few-bit data individually and then transmitted to a fusion center (FC), where a generalized likelihood ratio test (GLRT) detector is employed to achieve target detection and maximum likelihood estimation of the target location simultaneously. In this context, we first develop a GLRT detector using one-bit quantized data which is shown to outperform the typical counting rule and the detection scheme based on the scan statistic. We further propose a GLRT detector based on adaptive multi-bit quantization, where the sensor observations are more precisely quantized, and the quantized data can be efficiently transmitted to the FC. The Cramer-Rao lower bound (CRLB) of the estimate of target location is also derived for the GLRT detector. The simulation results show that the proposed GLRT detector with adaptive 2-bit quantization achieves much better performance than the GLRT based on one-bit quantization, at the cost of only a minor increase in communication overhead.

An Energy Balanced and Lifetime Extended Routing Protocol for Underwater Sensor Networks.

Energy limitation is an adverse problem in designing routing protocols for underwater sensor networks (UWSNs). To prolong the network lifetime with limited battery power, an energy balanced and efficient routing protocol, called energy balanced and lifetime extended routing protocol (EBLE), is proposed in this paper. The proposed EBLE not only balances traffic loads according to the residual energy, but also optimizes data transmissions by selecting low-cost paths. Two phases are operated in the EBLE data transmission process: (1) candidate forwarding set selection phase and (2) data transmission phase. In candidate forwarding set selection phase, nodes update candidate forwarding nodes by broadcasting the position and residual energy level information. The cost value of available nodes is calculated and stored in each sensor node. Then in data transmission phase, high residual energy and relatively low-cost paths are selected based on the cost function and residual energy level information. We also introduce detailed analysis of optimal energy consumption in UWSNs. Numerical simulation results on a variety of node distributions and data load distributions prove that EBLE outperforms other routing protocols (BTM, BEAR and direct transmission) in terms of network lifetime and energy efficiency.

A Novel Cross-Layer Routing Protocol Based on Network Coding for Underwater Sensor Networks.

Underwater wireless sensor networks (UWSNs) have attracted increasing attention in recent years because of their numerous applications in ocean monitoring, resource discovery and tactical surveillance. However, the design of reliable and efficient transmission and routing protocols is a challenge due to the low acoustic propagation speed and complex channel environment in UWSNs. In this paper, we propose a novel cross-layer routing protocol based on network coding (NCRP) for UWSNs, which utilizes network coding and cross-layer design to greedily forward data packets to sink nodes efficiently. The proposed NCRP takes full advantages of multicast transmission and decode packets jointly with encoded packets received from multiple potential nodes in the entire network. The transmission power is optimized in our design to extend the life cycle of the network. Moreover, we design a real-time routing maintenance protocol to update the route when detecting inefficient relay nodes. Substantial simulations in underwater environment by Network Simulator 3 (NS-3) show that NCRP significantly improves the network performance in terms of energy consumption, end-to-end delay and packet delivery ratio compared with other routing protocols for UWSNs.

A Network Coding Based Hybrid ARQ Protocol for Underwater Acoustic Sensor Networks.

Underwater Acoustic Sensor Networks (UASNs) have attracted increasing interest in recent years due to their extensive commercial and military applications. However, the harsh underwater channel causes many challenges for the design of reliable underwater data transport protocol. In this paper, we propose an energy efficient data transport protocol based on network coding and hybrid automatic repeat request (NCHARQ) to ensure reliability, efficiency and availability in UASNs. Moreover, an adaptive window length estimation algorithm is designed to optimize the throughput and energy consumption tradeoff. The algorithm can adaptively change the code rate and can be insensitive to the environment change. Extensive simulations and analysis show that NCHARQ significantly reduces energy consumption with short end-to-end delay.

Irreversible Electroporation Improves Tendon Healing in a Rat Model of Collagenase-Induced Achilles Tendinopathy.

BACKGROUND: Treatment of painful chronic tendinopathy is challenging, and there is an urgent need to develop new regenerative methods. Irreversible electroporation (IRE) can lead to localized cell ablation by electrical pulses and induce new cell and tissue growth. Previously, the authors' group reported that electroporation-ablated tendons fully regenerated. PURPOSE: To assess the efficiency of IRE in improving tendon healing using a collagenase-induced Achilles tendinopathy rat model. STUDY DESIGN: Controlled laboratory study. METHODS: After screening for the IRE ablation parameters, a collagenase-induced Achilles tendinopathy rat model was used to assess the efficacy of IRE in improving tendon healing via biomechanical, behavioral, histological, and immunofluorescence assessments. RESULTS: The experiments showed that the parameter of 875 V/cm 180 pulses could ablate most tenocytes, and apoptosis was the main type of death in vitro. In vivo, IRE promoted the healing process of chronic tendinopathy in the Achilles tendon of rats, based on biomechanical, behavioral, and histological assessments. Finally, immunofluorescence results revealed that IRE improved blood supply in the early stages of tendon repair and could potentially reduce neuropathic pain. CONCLUSION: IRE enhanced tendon tissue healing in a rat model of collagenase-induced Achilles tendinopathy. CLINICAL RELEVANCE: IRE may as a potential alternative treatment for tendinopathy in clinical usage.

[Effect and mechanisms of vitamin E on early steroid-induced avascular necrosis of femoral head in rats].

OBJECTIVE: To investigate the possibility of mitochondria-dependent apoptosis as a mechanism of early steroid-induced avascular necrosis of femoral head (SANFH) in rats and vitamin E as a possible prevention strategy. METHODS: Seventy-two male Sprague Dawley rats were randomly divided into control group, model group, and intervention group, with 24 rats in each group. The rats in control group were not treated as normal control. The rats in model group and intervention group were established early SANFH models by lipopolysaccharide combined with methylprednisolone injection. At the same time, the rats in intervention group were injected with vitamin E (40 mg/kg) every day for 7 days. At 2, 4, and 8 weeks after the final injection, the bilateral femoral heads were harvested and observed by HE staining, TUNEL assay, immunohistochemical staining, and Western blot. The rate of empty lacunae, apoptotic index, and the expressions of Caspase-9, Caspase-3, and cytochrome-c (Cyt-c) proteins were calculated. RESULTS: According to histological staining, there were significant differences in the rate of empty lacunae between intervention group and control group at 8 weeks ( P<0.05) and between intervention group and model group at 4 and 8 weeks ( P<0.05). The apoptotic index of intervention group was significantly lower than that of model group at each time point ( P<0.05). And there was significant difference between the intervention group and the control group at 8 weeks ( P<0.05). According to immunohistochemistry staining and Western blot, the expressions of Cyt-c, Caspase-9, and Caspase-3 all significantly decreased in intervention group than those in model group at each time point ( P<0.05); and the differences were significant between intervention group and control group at 8 weeks ( P<0.05). CONCLUSION: Vitamin E can delay the progression of early SANFH by reducing mitochondrial dependent osteocyte apoptosis.

Effects of periarticular injection on analgesic effects and NSAID use in total knee arthroplasty and total hip arthroplasty.

OBJECTIVES: This study examined periarticular multimodal drug injection and the use of nonsteroidal anti-inflammatory drugs for an early analgesic effect after total knee arthroplasty and total hip arthroplasty. Patient satisfaction and benefits from the treatment were also assessed. METHODS: A total of 110 patients who were scheduled to undergo total knee arthroplasty and 86 patients who were scheduled to undergo total hip arthroplasty were divided into two groups, the study group and the control group. The study group received a periarticular multimodal drug injection during surgery. The control group received an equal volume of normal saline. All patients received an analgesia pump and a moderate dose of nonsteroidal anti-inflammatory drugs. Resting and motion Numeric Rating Scale scores, the Western Ontario and McMaster Universities Arthritis Index, knee or hip joint range of motion, length of postoperative hospital stay, patient satisfaction, total nonsteroidal anti-inflammatory drug consumption and side effects were recorded. RESULTS: Both study groups exhibited significant improvement in pain Numeric Rating Scale scores during rest and exercise several days after the surgery. The range of joint motion was greater in the study group, and the length of postoperative hospital stay was shorter than that in the control group. Patients in the study group consumed fewer nonsteroidal anti-inflammatory drugs and reported greater satisfaction with surgery. CONCLUSION: Intraoperative periarticular multimodal drug injection significantly relieved pain after surgery and reduced nonsteroidal anti-inflammatory drug consumption. These patient had a better postoperative experience, including satisfaction and rehabilitation.

[EFFECT OF MACROPHAGE MIGRATION INHIBITORY FACTOR ON VASCULAR REPAIR OF STEROID-INDUCED AVASCULAR NECROSIS OF FEMORAL HEAD IN VITRO].

OBJECTIVE: To interpret the mechanisms of vascular repair disorders in steroid-induced avascular necrosis of the femoral head (SANFH) via detection of the changes of proliferation, migration, and macrophage migration inhibitory factor (MIF)/vascular endothelial growth factor (VEGF) expressions of endothelial cells (ECs) under hypoxia/glucocorticoid. METHODS: According to culture conditions, human umbilical vein ECs (HUVECs) at passage 3 were divided into group A (normal), group B (1.0×10-6 mol/L dexamethasone), group C (hypoxia), and group D (hypoxia+1.0×10-6 mol/L dexamethasone). The cell activity was detected by AlamarBlue; the number of viable cells was detected in live/dead cell staining; the cell morphology was observed after cytoskeleton staining; cell migration ability was compared by scratch test; and the levels of MIF and VEGF expressions were detected by ELISA. RESULTS: At 24 hours after culture, the cell activity and the number of living cells in group C were significantly higher than those in the other 3 groups, showing significant difference between groups (P<0.05), and group D had the worst cell activity and least living cells. Cytoskeleton staining showed that cells had normal morphology in groups A and B; cells had rich cytoskeleton and secretion granules in group C; cytoskeleton form disorder and nucleus pyknosis were observed in group D. Scratch test showed that the cell migration ability of group C was strongest while cell migration ability of group D was weakest. Accumulated concentration of MIF and VEGF in 4 groups significantly increased with time extending. Accumulated concentration of MIF in group C were significantly higher than that in other 3 groups at each time point (P<0.05). Within 24 hours after intervention, stage concentration of MIF during 1-8 hours was significantly lower than that during 0-1 hour and 8-24 hours in every group (P<0.05). Stage concentration of MIF in group C was significantly higher than other groups during 0-1 hour and 8-24 hours (P<0.05). Within 2 hours after intervention, stage concentration of MIF in 4 groups during 0.5-1 hour was significantly higher than that during other stages (P<0.05). Accumulated concentration of VEGF in group C was significantly higher than that in other groups at 8 and 24 hours (P<0.05). The stage concentration of VEGF in groups C and D during 8-24 hours was significantly higher than that during 0-1 hour and 1-8 hours (P<0.05). There was no significant difference in the stage concentration of VEGF within and among group A, B, C, and D at every stage within 2 hours after intervention (P>0.05). CONCLUSIONS: In hypoxia environment, the proliferation and migration of ECs is enhanced, and the secretion of VEGF and MIF is increased. High concentration of dexamethasone will suppress the process above, which induces vascular repair disorders and aggravating SANFH.

[EFFECT OF Wnt/ß-catenin SIGNAL PATHWAY ON APOPTOSIS IN STEROID-INDUCED AVASCULAR NECROSIS OF FEMORAL HEAD IN RATS].

OBJECTIVE: To investigate the effect of Wnt/ß-catenin signal pathway on the apoptosis in steroid-induced avascular necrosis of femoral head (SANFH) in rats. METHODS: Seventy-two male Sprague Dawley rats (weighing, 200-230 g) were randomly divided into the control group (group A, n=24), the model group (group B, n=24), and the intervening group (group C, n=24). The rats in groups B and C were injected with lipopolysaccharide and methylprednisolone (MPS) to establish the SANFH model. The rats in group C were injected intramuscularly with human recombinant secreted frizzled related protein 1 (SFRP1) [1 µg/(kg·d)] at the first time of MPS administration for 30 days. The rats in group A received saline injection at the same injection time of group B. The general condition of rats in groups B and C was observed during modeling and after modeling. At 2, 4, and 8 weeks after last injection of MPS, 8?rats were sacrificed to harvest the femoral head. Histological staining was performed to evaluate osteonecrosis. Apoptosis was detected via TUNEL staining. The expressions of Wnt/ß-cate nin pathway signaling molecules (activated ß-catenin and c-Myc) were detected by immunohistochemistry and Western blot. RESULTS: Six rats were added in groups B and C because of 6 deaths. The other rats survived to the end of experiment. Normal bone structure was observed in group A; osteonecrosis of bone structure disturbance and disruption of the trabecula were found with time in groups B and C. Group C had the highest empty lacuna rate and apoptosis rate, followed by groups B and A, showing significant difference between groups (P < 0.05). The expression levels of activated ß-catenin and c-Myc were significantly lower in group C than groups A and B (P < 0.05), and in group B than group A (P < 0.05). CONCLUSIONS: Wnt/ß-catenin signal pathway is involved in the pathogenesis in early SANFH model and its?possible mechanism?is to affect the cell cycle and cell apoptosis by the regulation of c-Myc expression.

Effects of periarticular injection on analgesic effects and NSAID use in total knee arthroplasty and total hip arthroplasty

OBJECTIVES: This study examined periarticular multimodal drug injection and the use of nonsteroidal anti-inflammatory drugs for an early analgesic effect after total knee arthroplasty and total hip arthroplasty. Patient satisfaction and benefits from the treatment were also assessed. METHODS: A total of 110 patients who were scheduled to undergo total knee arthroplasty and 86 patients who were scheduled to undergo total hip arthroplasty were divided into two groups, the study group and the control group. The study group received a periarticular multimodal drug injection during surgery. The control group received an equal volume of normal saline. All patients received an analgesia pump and a moderate dose of nonsteroidal anti-inflammatory drugs. Resting and motion Numeric Rating Scale scores, the Western Ontario and McMaster Universities Arthritis Index, knee or hip joint range of motion, length of postoperative hospital stay, patient satisfaction, total nonsteroidal anti-inflammatory drug consumption and side effects were recorded. RESULTS: Both study groups exhibited significant improvement in pain Numeric Rating Scale scores during rest and exercise several days after the surgery. The range of joint motion was greater in the study group, and the length of postoperative hospital stay was shorter than that in the control group. Patients in the study group consumed fewer nonsteroidal anti-inflammatory drugs and reported greater satisfaction with surgery. CONCLUSION: Intraoperative periarticular multimodal drug injection significantly relieved pain after surgery and reduced nonsteroidal anti-inflammatory drug consumption. These patient had a better postoperative experience, including satisfaction and rehabilitation.