Ecological risk assessment and early warning of heavy metal cumulation in the soils near the Luanchuan molybdenum polymetallic mine concentration area,Henan Province,central China

The Luanchuan molybdenum polymetallic mine concentration area is rich in mineral resources and has a long history of mining.The environmental impact of long-term mining activities cannot be ignored.It is of great significance to study the ecological risk and the accumulation trends of heavy metals in the soil of mining areas for scientific prevention and control of heavy metal pollution.Taking the Taowanbeigou River Basin in the mine concentration area as the research object,the ecological pollution risk and cumulative effect of heavy metals in the soil of the basin were studied by using the comprehensive pollution index method,potential ecological risk assessment method and geoaccumulation index method.On this basis,the cumulative exceeding years of specific heavy metals were predicted by using the early warning model.The comprehensive potential ecological risk of heavy metals in the soil near the Luanchuan mine concentration area is moderate,and the single element Cd is the main ecological risk factor,with a contribution rate of 53.6%.The overall cumulative degrees of Cu and Pb in the soil are“none-moderate”,Zn and Cd are moderate,Mo has reached an extremely strong cumulative level,Hg,As and Cr risks are not obvious,and the overall cumulative risks order is Mo>Cd>Zn>Cu>Pb>Hg.According to the current accumulation rate and taking the risk screening values for soil contamination of agricultural land as the reference standard,the locations over standard rates of Cu,Zn and Cd will exceed 78%in 90years,and the over standard rate of Pb will reach approximately 57%in 200 years.The cumulative exceeding standard periods of As,Cr and Hg are generally long,which basically indicates that these elements do not pose a significant potential threat to the ecological environment.Mining activities will accelerate the accumulation of heavy metals in soil.With the continuous development of mining activities,the potential pollution risk of heavy metals in the soil of mining areas will also increase.

Developmental and Reproductive Toxicity of Soybean Isoflavones to Immature SD Rats

Objective To investigate the dose-dependent toxic effect of soybean isoflavone extracts （SIE） on reproductive development in immature rats. Methods Growing male and female rats （n=50 each, 4 weeks） were divided into five groups fed with a standard cereal-based diet and gastrogavaged daily with 0, 30, 150, 300, and 600 mg SIE / kg body weight, respectively, for 12 weeks. Body weight, organ weights, and serum level of estrogen and testosterone were measured. Results Oral administration of SIE had no effect on food intake but decreased food efficiency ratio （P〈0.01）. Suppression on body weight gain by SIE was dose-dependent and the effect was greater on male than on female rats （P〈0.01）. SIE at high doses exhibited hepatotoxicity by increasing a relative liver weight, and also caused a smaller uterus but a greater relative ovary in female rats, while leading to larger relative testis and epididymis in male rats. SIE could decrease progesterone concentrations in female rats, whereas in male rats it reduced not only total testosterone level but also sperm count compared with the control group （P〈0.05）. Conclusion SIE at a range of 50-1000 times of human intake level affects not only growth but also development of reproductive system in growing rats.

DHA Depletion in Rat Brain Is Associated With Impairment on Spatial Learning and Memory

Objective To examine the effect of docosahexaenoic acid （DHA） deficiency in brain on spatial learning and memory in rats. Methods Sprague Dawley rats were fed with an n-3 fatty acid deficient diet for two generations to induce DHA depletion in brain, DHA in seven brain regions was analyzed using the gas-liquid chromatography. Morris water maze （MWM） was employed as an assessing index of spatial learning and memory in the n-3 fatty acid deficient adult rats of second generation. Results Feeding an n-3 deficient diet for two generations depleted DHA differently by 39%-63% in the seven brain regions including cerebellum, medulla, hypothalamus, striatum, hippocampus, cortex and midbrain, The MWM test showed that the n-3 deficient rats took a longer time and swam a longer distance to find the escape platform than the n-3 Adq group. Condusion The spatial learning and memory in adult rats are partially impaired by brain DHA depletion.

Soft tissue release combined with joint-sparing osteotomy for treatment of cavovarus foot deformity in older children: Analysis of 21 cases

BACKGROUND Cavovarus foot is a common form of foot deformity in children,which is clinically characterized by an abnormal increase of the longitudinal arch of the foot,and it can be simultaneously complicated with forefoot pronation and varus,rearfoot varus,Achilles tendon contracture,or cock-up toe deformity.Muscle force imbalance is the primary cause of such deformity.Many diseases can lead to muscle force imbalance,such as tethered cord syndrome,cerebral palsy,Charcot-Marie-Tooth disease,and trauma.At present,many surgical treatments are available for cavovarus foot.For older children,priority should be given to midfoot osteotomy and fusion.Since complications such as abnormal foot length,foot stiffness,and abnormal gait tend to develop postoperatively,it is important to preserve the joints and correct the deformity as much as possible.Adequate soft tissue release and muscle balance are the keys to correcting the deformity and avoiding its postoperative recurrence.AIM To assess the efficacy of soft tissue release combined with joint-sparing osteotomy in the treatment of cavovarus foot deformity in older children.METHODS The clinical data of 21 older children with cavovarus foot deformity(28 feet)who were treated surgically at the Ninth Department of Orthopedics of Jizhong Energy Xingtai Mining Group General Hospital from November 2014 to July 2017 were retrospectively analyzed.The patients ranged in age from 10 to 14 years old,with an average age of 12.46±1.20 years.Their main clinical manifestations were deformity,pain,and gait abnormality.The patients underwent magnetic resonance imaging of the lumbar spine,electromyographic examination,weightbearing anteroposterior and lateral X-rays of the feet,and the Coleman block test.Surgical procedures including metatarsal fascia release,Achilles tendon or medial gastrocnemius lengthening,"V"-shaped osteotomy on the dorsal side of the metatarsal base,opening medial cuneiform wedge osteotomy,closing cuboid osteotomy,anterior transfer of the posterior tibial tendon,peroneus longus-tobrevis transfer,and calcaneal sliding osteotomy to correct hindfoot varus deformity were performed.After surgery,long leg plaster casts were applied,the plaster casts were removed 6 wk later,Kirschner wires were removed,and functional exercise was initiated.The patients began weight-bearing walk 3 mo after surgery.Therapeutic effects were evaluated using the Wicart grading system,and Meary’s angles and Hibbs’angles were measured based on X-ray images obtained preoperatively and at last follow-up to assess their changes.RESULTS The patients were followed for 6 to 32 mo,with an average follow-up period of 17.68±6.290 mo.Bone healing at the osteotomy site was achieved at 3 mo in all cases.According to the Wicart grading system,very good results were achieved in 18 feet,good in 7,and fair in 3,with a very good/good rate of 89.3%.At last follow-up,mean Meary’s angle was 6.36°±1.810°,and mean Hibbs’angle was 160.21°±4.167°,both of which were significantly improved compared with preoperative values(24.11°±2.948°and 135.86°±5.345°,respectively;P<0.001 for both).No complications such as infection,skin necrosis,or bone nonunion occurred.CONCLUSION Soft tissue release combined with joint-sparing osteotomy has appreciated efficacy in the treatment of cavovarus foot deformity in older children.

Double balloon enteroscopy in the old: Experience from China

AIM: To evaluate the safety, efficacy and management of double balloon enteroscopy (DBE) carried out in those aged individuals with suspicious small intestine diseases. METHODS: DBE is a wonderful invention of the past decade and is widely used as an examination tool for the gastrointestinal tract. From January 2003 to July 2011, data from patients who were ≥ 65 years old and underwent DBE examination in the Nanfang Hospital were included in a retrospective analysis.RESULTS: Fifty-nine individuals were found and subsequently analyzed. The mean age was 69.63 ± 3.89 years (range 65-84), 34 were males. Indications for DBE were melena/hematochezia (36 cases), abdominal pain (15 cases), diarrhea (3 cases), stool change (1 case), weight loss (1 case), vomiting (2 cases), and debilitation (1 case). The average duration of symptoms was 33.34 ± 64.24 mo. Twenty-seven patients suffered from age-related diseases. Severe complications were not found during and after DBE. Comparison between systolic and diastolic blood pressure before and after DBE was statistically significant (mean ± SD, P < 0.01, P < 0.05, respectively). Small bowel pathologies were found by DBE in 35 patients, definite diagnoses were made in 31 cases, and detection rate and diagnostic yield for DBE were 68.6% and 60.8%, respectively. CONCLUSION: DBE is a safe and effective method for gastrointestinal examination in the aged population. Aging alone is not a risk factor for elderly patients with suspicious gastrointestinal diseases and thorough preparation prior to the DBE procedure should be made for individuals with multiple diseases especially cardiopulmonary disorders.

Low-loss belief propagation decoder with Tanner graph in quantum error-correction codes

Quantum error-correction codes are immeasurable resources for quantum computing and quantum communication.However,the existing decoders are generally incapable of checking node duplication of belief propagation(BP)on quantum low-density parity check(QLDPC)codes.Based on the probability theory in the machine learning,mathematical statistics and topological structure,a GF(4)(the Galois field is abbreviated as GF)augmented model BP decoder with Tanner graph is designed.The problem of repeated check nodes can be solved by this decoder.In simulation,when the random perturbation strength p=0.0115-0.0116 and number of attempts N=60-70,the highest decoding efficiency of the augmented model BP decoder is obtained,and the low-loss frame error rate(FER)decreases to 7.1975×10^(-5).Hence,we design a novel augmented model decoder to compare the relationship between GF(2)and GF(4)for quantum code[[450,200]]on the depolarization channel.It can be verified that the proposed decoder provides the widely application range,and the decoding performance is better in QLDPC codes.

Effects of initial states on the quantum correlations in the generalized Grover search algorithm

We investigate the correlations between two qubits in the Grover search algorithm with arbitrary initial states by numerical simulation.Using a set of suitable bases,we construct the reduced density matrix and give the numerical expression of correlations relating to the iterations.For different initial states,we obtain the concurrence and quantum discord compared with the success probability in the algorithm.The results show that the initial states affect the correlations and the limit point of the correlations in the searching process.However,the initial states do not influence the whole cyclical trend.

Comparison of hand-assisted laparoscopic radical gastrectomy and laparoscopic-assisted radical gastrectomy:A systematic review and meta-analysis

BACKGROUND Gastrectomy is the optimal treatment for gastric cancer.Laparoscopic-assisted gastrectomy(LAG)has been extensively employed,while hand-assisted laparoscopic gastrectomy(HALG),which is similar to LAG,remains controversial.Although HALG is popular in China,some surgeons do not accept it as a minimal-access technique.AIM To assess the safety and practicability of HALG by comparing the short-term outcomes of HALG and LAG.METHODS The electronic databases of EMBASE,PubMed,China National Knowledge Infrastructure,and Cochrane Library were thoroughly searched,and randomized controlled trials(RCTs)comparing HALG and LAG were included.The study results,including surgery time,blood loss,retrieved lymphatic nodes,incision length,time to first flatus,hospitalization duration,and all postsurgical complications,were compared between the two groups.RESULTS Five RCTs,which included 302 cases with HALG and 298 cases with LAG,were considered eligible for inclusion.Meta-analysis showed that HALG significantly reduced surgery time(P<0.01),hospital duration(P<0.01),and overall postsurgical complications(P<0.01).Additionally,HALG significantly increased the number of retrieved lymphatic nodes(P=0.01)and incision length(P<0.01)compared with LAG.The blood loss and time to first flatus were similar between the two groups(P>0.05).CONCLUSION Compared with LAG,HALG is a simpler and safer technique.Additionally,HALG should be used as a minimal-access technique,especially in technologically undeveloped areas.

Large-scale synthesis of low-cost 2D metal–organic frameworks for highly selective photocatalytic CO_(2)reduction

Two-dimensional metal–organic frameworks(2D MOFs),as a new type of 2D materials,have been widely applied in various applications because of their unique structures and exposed active sites.Herein,we reported two low-cost 2D MOFs constructed by a raw chemical succinic acid(SA),M-SA(M=Ni or Co),which served as efficient photocatalysts for the reduction of CO_(2)to CO.Taking advantage of the thinness and open metal sites,the ultrathin Ni-SA nanosheets(ca.3.6 nm)exhibited excellent CO production of 6.96(7)mmol·g^(−1)·h^(−1)and CO selectivity of 96.6%.Photoelectrochemical tests and theoretical calculations further confirmed the higher charge transfer efficiency and unsaturated metal sites for promoting photocatalytic performances.More importantly,Ni-SA can also be synthesized in large-scale by an energy-saving method under room temperature,strongly suggesting its promising future and potential for practical applications.

PTM： A Topic Model for the Inferring of the Penalty

Deciding the penalty of a law case has always been a complex process, which may involve with much coordination. Despite the judicial study based on the rules and conditions, artificial intelligence and machine learning has rarely been used to study the problem of penalty inferring, leaving the large amount of law cases as well as various factors among them untouched. This paper aims to incorporate the state-of-the-art artificial intelligence methods to exploit to what extent this problem can be alleviated. We first analyze 145 000 law cases and observe that there are two sorts of labels, temporal labels and spatial labels, which have unique characteristics. Temporal labels and spatial labels tend to converge towards the final penalty, on condition that the cases are of the same category. In light of this, we propose a latent-class probabilistic generative model, namely Penalty Topic Model （PTM）, to infer the topic of law cases, and the temporal and spatial patterns of topics embedded in the case judgment. Then, the learnt knowledge is utilized to automatically cluster all cases accordingly in a unified way. We conduct extensive experiments to evaluate the performance of the proposed PTM on a real large-scale dataset of law cases. The experimental results show the superiority of our proposed PTM.

Physics perspectives of heavy-ion collisions at very high energy

Heavy-ion collisions at very high colliding energies are expected to produce a quark-gluon plasma(QGP) at the highest temperature obtainable in a laboratory setting. Experimental studies of these reactions can provide an unprecedented range of information on properties of the QGP at high temperatures. We report theoretical investigations of the physics perspectives of heavy-ion collisions at a future high-energy collider. These include initial parton production, collective expansion of the dense medium, jet quenching,heavy-quark transport, dissociation and regeneration of quarkonia, photon and dilepton production. We illustrate the potential of future experimental studies of the initial particle production and formation of QGP at the highest temperature to provide constraints on properties of strongly interaction matter.

A modified bilobed flap design for nasal tip defects

Aim:The correction of nasal tip defects presents many challenges.Zitelli’s bilobed flap has been widely used for such repairing defects,but may be complicated by interrupted scars on the nasal dorsum.Our study evaluates the design principles,results,and advantages of a modified bilobed flap for repairing nasal tip defects.Methods:The primary lobe was located between the defect and the cheek,and the second lobe was located in the cheek.The width of the primary lobe was equal to that of the primary defect.The length of the primary lobe was 10%longer than the distance of the distal defect edge to the pivot point of the flap.The length of the second lobe was 30%longer than the distance of the distal defect edge to the pivot point of the flap.The width of the second lobe was 90-100%of that of the primary lobe.The ability to close the defect under minimal tension,the cosmetic appearance,and any complications were evaluated.Results:This technique was performed in 34 cases;defect size ranged from 0.8 cm×0.9 cm to 1.2 cm×1.8 cm.All defects were closed under minimal wound tension,all scars were inconspicuous,no obvious complications occurred,and the aesthetic outcomes were considered favorable.Conclusion:The modified bilobed flap can provide satisfying outcomes with lower morbidity and inconspicuous scarring.It is simple and suitable for repairing small-to medium-sized defects in the nasal tip.