Effect of oxygen-containing functional group contents on sorption of lead ions by acrylate-functionalized hydrochar.

The surface functional groups of hydrochar are crucial to its surface properties, and their contents are strongly positively correlated with the adsorption performance. In this study, acrylate-functionalized hydrochar (AHC) with varying contents of O-containing functional groups (OFGs) was synthesized via hydrothermal carbonization (HTC) of bamboo, acrylic acid and an initiator, and then deprotonated with NaOH. The AHCs were analyzed by various characterization techniques. During HTC, the higher amount of acrylic acid added led to higher carbon, oxygen and carboxyl contents, and to the larger specific surface area and pore volume of AHC. The adsorption kinetics, isotherms, thermodynamic, ionic strength and pH effects of Pb(II) on AHC were studied. Adsorption isotherms and kinetics obeyed Langmuir and pseudo-second-order models, respectively, indicating adsorption is monolayer chemical process. The adsorptive ability was well linearly related to the OFG contents of AHC. When acrylic acid was added to 25 mL during HTC, the adsorbing ability of AHC over Pb(II) reached 193.90 mg g-1. Hence, direct HTC of acrylic acid, biomass and an initiator can prepare hydrochar with controllable OFG contents, which is a prospective adsorbent for treating metal cations.

Multi-mode coupled vibration analysis and radiation sound field investigation of a novel multidirectional piezoelectric ultrasonic transducer.

Nowadays, expanding the operating range and realizing multifrequency operation have emerged as focal and imperative objectives in the design of ultrasonic transducers. Due to the limitations of structure and radial sizes, conventional Langevin transducers encounter challenges in meeting the increasingly stringent requirements across diverse ultrasonic applications. Hence, this paper proposes a multidirectional piezoelectric ultrasonic transducer (MPUT) consisting of a large-dimension sandwich piezoelectric transducer (LSPT) and a metal tube in mutli-mode coupled vibration, capable of achieving wide-ranging and multifrequency acoustic radiation. Based on the analytical method, a two-dimensional electromechanical equivalent circuit model (2D-EECM) of the MPUT is established, and its frequency calculation results are validated through the finite element method (FEM) and impedance analysis experiment. The vibration testing results indicate that adjusting the radial size can control the coupled vibration intensity of the MPUT and achieve dual-frequency and multidirectional uniform radiation. The radiation sound field testing results confirm the MPUT's satisfactory three-dimensional radiation capability in water and significant improvement in acoustics operating range.

Comprehensive Gas Prevention and Control Technique for Mining the First Seam in Short-Distance Outburst Coal Seam Groups.

Coal and gas outbursts are a phenomenon whereby broken coal and gas suddenly erupt from the coal body into the mining space under pressure. The Diandong mining area is a group of close-range outburst coal seams in which the gas content is up to 20 m3/t and gas pressure can reach 3 MPa. Research has been conducted on engineering challenges such as advanced detection and prevention of interlayer excavation in close-range coal seam groups, improvement of gas extraction quality and efficiency in low-permeability coal seam groups, and traceability and evaluation of joint extraction of coal seam groups. Through this study, advanced detection technology with full coverage in front of the excavation working face has been constructed as well as advanced pre-extraction technology for adjacent coal seams and this coal seam in ultraclose layers. We have developed a method for achieving the standard of cross-layer fixed-point hole expansion and permeability enhancement for the first mining of coal seams in a coal seam group. A combined process of graded enhanced pre-extraction and segmented regulation and extraction was proposed, which included "fixed-point control section sealing pre-extraction of coal seam groups and secondary sealing and extraction of mining pressure relief orifice."

Optimized Reconstruction Procedure of Photoacoustic Imaging for Reflection Artifacts Reduction.

Photoacoustic (PA) imaging technology is of some value in medical diagnoses such as breast cancer detection, vasculature imaging, and surgery navigating. While as most imaging objects are bounded, the received RF signals consist of the direct-arrived signals (DAS) from the PA sources and the boundary-reflected signals (BRS). The undesired BRS will severely impair the quality during the image reconstruction. They will bring in many artifacts and confuse the actual shape and location of the PA sources. We improved the reconstruction procedure by removing the BRS before the regular reconstruction process to suppress those artifacts. To verify our proposed method, we compared the results of the conventional and optimized procedures experimentally. In terms of qualitative observation, the reconstructed images by the optimized procedure illustrate fewer artifacts and more accurate shapes of the PA sources. To quantitatively evaluate the traditional and the optimized imaging procedure, we calculated the Distribution Relative Error (DRE) between each experiment result and its standard drawing of the phantoms. For both phantoms and the ex-vivo sample, the DREs of reconstruction result by the optimized reconstruction procedure decrease significantly. The results suggest that the optimized reconstruction process can effectively suppress the reflection artifacts and improve the shape accuracy of the PA sources.

Radial oscillation and translational motion of a gas bubble in a micro-cavity.

According to classical nucleation theory, a gas nucleus can grow into a cavitation bubble when the ambient pressure is negative. Here, the growth process of a gas nucleus in a micro-cavity was simplified to two "events", and the full confinement effect of the surrounding medium of the cavity was considered by including the bulk modulus in the equation of state. The Rayleigh-Plesset-like equation of the cavitation bubble in the cavity was derived to model the radial oscillation and translational motion of the cavitation bubble in the local acoustic field. The numerical results show that the nucleation time of the cavitation bubble is sensitive to the initial position of the gas nucleus. The cavity size affects the duration of the radial oscillation of the cavitation bubble, where the duration is shorter for smaller cavities. The equilibrium radius of a cavitation bubble grown from a gas nucleus increases with increasing size of the cavity. There are two possible types of translational motion: reciprocal motion around the center of the cavity and motion toward the cavity wall. The growth process of gas nuclei into cavitation bubbles is also dependent on the compressibility of the surrounding medium and the magnitude of the negative pressure. Therefore, gas nuclei in a liquid cavity can be excited by acoustic waves to form cavitation bubbles, and the translational motion of the cavitation bubbles can be easily observed owing to the confining influence of the medium outside the cavity.

Molecular and Metabolic Mechanism of Low-Intensity Pulsed Ultrasound Improving Muscle Atrophy in Hindlimb Unloading Rats.

Low-intensity pulsed ultrasound (LIPUS) has been proved to promote the proliferation of myoblast C2C12. However, whether LIPUS can effectively prevent muscle atrophy has not been clarified, and if so, what is the possible mechanism. The aim of this study is to evaluate the effects of LIPUS on muscle atrophy in hindlimb unloading rats, and explore the mechanisms. The rats were randomly divided into four groups: normal control group (NC), hindlimb unloading group (UL), hindlimb unloading plus 30 mW/cm2 LIPUS irradiation group (UL + 30 mW/cm2), hindlimb unloading plus 80 mW/cm2 LIPUS irradiation group (UL + 80 mW/cm2). The tails of rats in hindlimb unloading group were suspended for 28 days. The rats in the LIPUS treated group were simultaneously irradiated with LIPUS on gastrocnemius muscle in both lower legs at the sound intensity of 30 mW/cm2 or 80 mW/cm2 for 20 min/d for 28 days. C2C12 cells were exposed to LIPUS at 30 or 80 mW/cm2 for 5 days. The results showed that LIPUS significantly promoted the proliferation and differentiation of myoblast C2C12, and prevented the decrease of cross-sectional area of muscle fiber and gastrocnemius mass in hindlimb unloading rats. LIPUS also significantly down regulated the expression of MSTN and its receptors ActRIIB, and up-regulated the expression of Akt and mTOR in gastrocnemius muscle of hindlimb unloading rats. In addition, three metabolic pathways (phenylalanine, tyrosine and tryptophan biosynthesis; alanine, aspartate and glutamate metabolism; glycine, serine and threonine metabolism) were selected as important metabolic pathways for hindlimb unloading effect. However, LIPUS promoted the stability of alanine, aspartate and glutamate metabolism pathway. These results suggest that the key mechanism of LIPUS in preventing muscle atrophy induced by hindlimb unloading may be related to promoting protein synthesis through MSTN/Akt/mTOR signaling pathway and stabilizing alanine, aspartate and glutamate metabolism.

Weight-bearing exercise prevents skeletal muscle atrophy in ovariectomized rats.

Skeletal muscle atrophy (SMA) is a dominant symptom induced by estrogen deficiency which can lead to severe health problems of postmenopausal women. Furthermore, estrogen deficiency has severely compromised the maintenance of muscle stem cells as well as impairs self-renewal and differentiation into muscle fibers. Resistance training is commonly considered as a positive and useful intervention in accelerating the rate of muscle growth. As one of the resistance training, whether the weight-bearing exercise can alleviate SMA induced by estrogen deficiency has not been investigated. The rats were divided into 3 groups randomly: sham group, ovariectomized (OVX) group, and weight-bearing exercise (WBE) therapeutic group. The weight that rats were loaded was 35% of their body weight, and the rats were trained by treadmill training (5° slope, 20 m/min, 30 min/day, 6 days/week) for 8 weeks. After training, the quality and strength of skeletal muscle of the WBE rats were improved; meanwhile, the cross-sectional areas of the skeletal muscle were also increased. Moreover, the WBE activated Akt significantly, upregulated the expression of mTOR, and downregulated the expression of MSTN and its receptor ActRIIB and FoxO1, respectively. The SMA phenomena of rats which induced by estrogen deficiency were prevented effectively via WBE, and the MSTN/Akt/mTOR and FoxO1 signaling pathway may be the predominant way in this improvement.

MSTN is a key mediator for low-intensity pulsed ultrasound preventing bone loss in hindlimb-suspended rats.

Low-intensity pulsed ultrasound (LIPUS) has been used to accelerate bone fracture healing. However, the issue whether LIPUS is effective in preventing osteoporosis has not been clarified, and if so, what possible mechanisms might be responsible. Myostatin (MSTN) is a negative regulator of muscle growth, and its absence will trigger a positive response to bone. In this study, we examined the effects of LIPUS on bone micro-structure, mechanical properties and damage healing of hindlimb-suspended rats, and investigated whether the inhibition of MSTN plays a role in this process. The rats were randomly divided into four groups: Normal control group (NC), Hind limb suspension group (HLS), Hind limb suspension and 80 mW/cm2 LIPUS irradiation group (HLS+ 80 mW/cm2), Hind limb suspension and 30 mW/cm2 LIPUS irradiation group (HLS+ 30 mW/cm2). The HLS+ 80 mW/cm2 rats were treated with LIPUS (1 MHz, 80 mW/cm2) and the HLS+ 30 mW/cm2 rats were treated with LIPUS (1 MHz, 30 mW/cm2) on the femur for 20 min/day for 28 days. MC3T3-E1 cells were respectively cultured with the serum of wild type mouse and MSTN knockout mouse at 1% concentration for 7 days. After 28 days, LIPUS effectively prevented the destruction of bone microstructure and the decline of mechanical properties, and promoted bone defect healing in the tail-suspended rats. In addition, LIPUS effectively reduced the MSTN content in the quadriceps and serum of the tail-suspended rats, inhibited its receptor and downstream signaling molecules and activated the Wnt signaling pathway in femurs. Growth of MC-3T3-E1 cell cultured with the serum of MSTN knockout mice was superior to that with wild mice serum on day 7. These results indicate that MSTN is a key mediator in LIPUS preventing bone loss caused by hindlimb-suspension.

Inhibition of MSTN signal pathway may participate in LIPUS preventing bone loss in ovariectomized rats.

INTRODUCTION: Menopause can lead to osteoporosis, which is characterized by destruction of bone microstructure, poor mechanical properties, and prone to fracture. LIPUS can effectively promote bone formation and fracture healing. MSTN is a transforming growth factor-ß family member that acts as a negative regulator of skeletal muscle growth. A MSTN deficiency also has a positive effect on bone formation. However, whether LIPUS could inhibit bone loss and promote healing of bone injury of menopause through the inhibition of the MSTN signaling pathway has not been previously investigated. We herein investigated the effects of LIPUS on bone architecture, mechanical properties, the healing of bone defects, and its potential molecular mechanisms in ovariectomized rats. MATERIALS AND METHODS: The rats were randomly divided into three groups: sham ovariectomized group (Sham), ovariectomized model group (OVX), ovariectomized model with LIPUS therapy group (OVX + LIPUS). The OVX + LIPUS rats were treated with LIPUS (1.5 MHz, 30 mW/cm2) on the femur for 20 min/day that lasted for 19 days. RESULTS: LIPUS effectively improved the bone microstructure, increased mechanical properties and promoted the healing of bone defects in ovariectomized rats. Moreover, LIPUS effectively decreased the MSTN content in serum and quadriceps muscle in ovariectomized rats, and inhibited the expression of MSTN downstream signaling molecules and activated the Wnt signaling pathway in the femur. CONCLUSIONS: The present study shows that LIPUS improved osteoporosis and promoted bone defect healing in the ovariectomized rats may through the inhibition of the MSTN signal pathway.

Inhibition of myostatin signal pathway may be involved in low-intensity pulsed ultrasound promoting bone healing.

PURPOSE: Low-intensity pulsed ultrasound (LIPUS) is effective in promoting bone healing, and a myostatin deficiency also has a positive effect on bone formation. In this study, we evaluated the effects of LIPUS on bone healing in rats in vivo and investigated the mechanisms in vitro, aiming to explore whether LIPUS promotes bone healing through inhibition of the myostatin signaling pathway. METHODS: Rats with both drill-hole defects and MC3T3-E1 cells were randomly assigned to a LIPUS group and a control group. The LIPUS group received LIPUS treatment (1.5 MHz, 30 mW/cm2) for 20 min/day. RESULTS: After 21 days, the myostatin expression in quadriceps was significantly inhibited in the LIPUS group, and remodeling of the newly formed bone in the drill-hole site was significantly better in the LIPUS group than that in the control group, which was confirmed by micro-CT analysis. After 3 days, LIPUS significantly promoted osteoblast proliferation; inhibited the expression of AcvrIIB (the myostatin receptor), Smad3, p-Smad3, and GSK-3ß; and increased Wnt1 and ß-catenin expression. Moreover, translocation of ß-catenin from the cytolemma to the nucleus was observed in the LIPUS group. However, these effects were blocked by treatment with myostatin recombinant protein. CONCLUSIONS: The results indicate that LIPUS may promote bone healing through inhibition of the myostatin signal pathway.

Low-intensity pulsed ultrasound prevents muscle atrophy induced by type 1 diabetes in rats.

BACKGROUND: Type 1 diabetes mellitus (T1DM) induces serious skeletal muscle atrophy. Low-intensity pulsed ultrasound (LIPUS) is a common treatment for skeletal muscle injury and is effective in accelerating the rate of muscle growth. However, to the best of our knowledge, whether LIPUS can improve skeletal muscle atrophy in type 1 diabetic rats has not been investigated. METHODS: The rats were randomly divided into four groups: the normal control group (NC); the sham-treated diabetic control group (DC); the diabetic, insulin-treated group (DI) as a positive control; and the diabetic LIPUS therapy group (DL). The DL rats were treated with LIPUS (1 MHz, 30 mW/cm2) on the gastrocnemius for 20 min/day. RESULTS: After 6 weeks, the rats in the DC group showed severe muscle atrophy. However, LIPUS significantly improved type 1 diabetes-induced muscle atrophy, as evidenced by significantly enhanced muscle cross-sectional area, muscle mass, and strength. Moreover, compared with the DC group, LIPUS significantly activated Akt and upregulated the expression of mTOR, and LIPUS downregulated the expression of MSTN, its receptor ActRIIB, and FoxO1. CONCLUSIONS: These results indicate that LIPUS improved muscle atrophy induced by type 1 diabetes, and the MSTN/Akt/mTOR&FoxO1 signaling pathway may play a role in this improvement.

Low-Intensity Pulsed Ultrasound Promotes Exercise-Induced Muscle Hypertrophy.

The purpose of this study was to investigate whether low-intensity pulsed ultrasound (LIPUS) promotes exercise-induced muscle hypertrophy. Twenty-four adult Sprague-Dawley (SD) rats were randomly assigned to three groups (n = 8 per group): normal control group (NC), treadmill exercise group (TE) and treadmill exercise + LIPUS group (TE + LIPUS). The TE + LIPUS group received a LIPUS treatment (1 MHz, 30 mW/cm2) at the gastrocnemius for 20 min/d after treadmill exercise. The TE group was sham-treated. Eight weeks of treadmill training successfully established the exercise-induced muscle hypertrophy model. Muscle strength, muscle mass and muscle fiber cross-sectional area were significantly increased in the TE + LIPUS group compared with the TE group. Moreover, LIPUS treatment significantly upregulated the expression of Akt, mTOR, p-Akt and p-mTOR and significantly downregulated the expression of MSTN, ActRIIB, FoxO1 and its phosphorylation. The results indicated that LIPUS promotes exercise-induced muscle hypertrophy by facilitating protein synthesis and inhibiting the protein catabolism pathway.

Role of magnetic resonance spectroscopy and susceptibility weighted imaging in cerebral alveolar echinococcosis.

BACKGROUND: To analyze the characteristic performance of magnetic resonance spectroscopy (MRS) and susceptibility weighted imaging (SWI) in cerebral alveolar echinococcosis (CAE). METHODS: We retrospectively analyzed 10 clinical-identified CAE cases MR performance, and summarized the MRS and SWI performance of CAE. RESULTS: The 10 cases of CAE all had the history of primary HAE, among who 6 cases had single lesion (60%), while the rest 4 cases had multiple lesions (40%); and 4 cases were concomitant with lung metastases. MRI performance: T2WI lesions were coal-like low-signal shadow, with multiple small vesicles inside the lesions; MRS performance: NAA, Cho and Cr significantly reduced, an abnormally high and steep crest was found at 1.4 ppm; the phase diagram and strength diagram of SWI showed isointensity. CONCLUSION: The MRS and SWI of CAE could provide important supplemental information for the diagnosis of CAE, especially the abnormally high and steep crest at 1.4 ppm provide the reliable image basis for the diagnosis and differential diagnosis of CAE.

[Neuroendoscopic management of tethered spinal cord syndrome].

OBJECTIVE: To investigate the methods and efficacy of neuroendoscopic operation in the treatment of tethered spinal cord syndrome (TSCS). METHODS: A total of 21 cases were recruited. There were 13 males and 8 females with an average age of 12.5 years old. TSCS was diagnosed by magnetic resonance imaging (MRI). They were operated under neuroendoscope. RESULTS: No complication was found during a follow-up period of 0.5 - 3 years. The symptoms improved in 18 cases. Neither obvious improvement nor aggravation was found in 3 cases. The total effective rate was 85.71%. CONCLUSION: Neuroendoscopic treatment of TSCS is both safe and effective.

A comparative study on in vitro and in vivo effects of topical vasodilators in human internal mammary, radial artery and great saphenous vein.

OBJECTIVE: As an important prognostic factor of coronary artery bypass grafting (CABG), graft vasospasm can be observed in all currently used graft conduits. Radial artery (RA) vasospasm is more prone to occur in comparisons with internal mammary artery (IMA) and great saphenous vein (GSV). There is still controversy about which antispasmodic agent is superior to different grafts, especially to RA conduits. The aim of this pilot study was to investigate the relaxation response of four topical vasodilators to different in vitro grafts and how these vasodilators affect the blood flow of the vessel in situ during RA harvesting. MATERIALS AND METHODS: Vasodilatory properties of diltiazem, nitroglycerin, urapidil and nicorandil were compared in matched patient-specific segments of RA, IMA and GSV harvested from 12 patients. The vasodilatory response of the RA to intraradial administration of nitroglycerin, diltiazem and urapidil was compared in vivo (n=10 per group) by assessing the free blood flow of RA. RESULTS: (1) The maximal relaxations occurring with urapidil, nitroglycerin and nicorandil in IMA, RA and SGV were significantly greater than that with diltiazem. The reactivity of all three graft conduits showed similar relaxation with nitroglycerin or with diltiazem, but the relaxation with urapidil in RA showed greater than that of IMA and GSV, and RA and GSV showed greater relaxation with nicorandil than IMA. (2) A dose of 10(-5)mol/l of nitroglycerin, urapidil and nicorandil but not diltiazem significantly inhibited the RA response to PE. (3) In vivo, urapidil and nitroglycerin significantly increased the RA blood flow, the potency of which was greater than that caused by diltiazem. CONCLUSIONS: (1) Comparing with nicorandil, urapidil and diltiazem, nitroglycerin caused a significant relaxation in all three graft vessels tested. (2) Nitroglycerin, nicorandil and urapidil were more effective in preventing RA spasm than diltiazem.

The putative tumor suppressor deleted in malignant brain tumors 1 is an estrogen-regulated gene in rodent and primate endometrial epithelium.

Deleted in malignant brain tumors 1 (DMBT1) is a candidate suppressor of malignancies of the brain, lung, gut, and breast. We have been studying gene expression in the uterus in the presence of estrogens and their antagonists. Here, we show that DMBT1 RNA levels are robustly increased by estrogen treatment in the uteri of ovariectomized monkeys and rats. In monkeys, the progestin antagonist mifepristone inhibits estrogen-dependent uterine proliferation. As determined by a microarray experiment and quantitative analysis of RNA levels, mifepristone inhibited estrogenic induction of DMBT1. DMBT1 was not expressed in intact monkeys that were treated with a gonadotropin agonist to suppress steroidogenesis. An in vitro transfection study with human DMBT1 promoter constructs showed that an Alu site approximately 3000 nucleotides upstream of the gene mediates estrogenic regulation. Surprisingly, the estrogen antagonists tamoxifen, raloxifene, and ICI 182,780 also induced gene expression via this Alu site. Rodents represent a more convenient model system for studying uterine biology than monkeys. In rats, uterine DMBT1 RNA levels were dramatically up-regulated by estrogen. Consistent with the transfection study, tamoxifen and raloxifene increased DMBT1 RNA levels in vivo, but ICI 182,780 inhibited an estrogen-induced increase. Immunohistochemical studies showed that DMBT1 is specifically induced in glandular and luminal epithelia of the rat endometrium. Our experiments establish that DMBT1 is an estrogen-responsive gene with a possible role in endometrial proliferation or differentiation, and they have implications for the putative tumor suppressive and mucosal protective functions of DMBT1 in the uterus.