三星电子量产20纳米级4Gb超高速移动DRAM

近日,三星电子正式投产超高速移动DRAM,移动DRAM将大幅提高设备的数据处理能力,新产品将用于今年上市的高配移动设备上。4月,三星电子在业内首次量产20纳米级（一纳米等于十亿分之一米）4Gb（Gigabit）LPDDR3（Low Power Double Data Rate3）移动DRAM。

二维b超对乳腺癌筛查的临床诊断价值

研究临床乳腺癌筛查使用二维b超检查的诊出率,并为适龄女性乳腺癌筛查和防治提供建议。方法:提取我院2019年1月-2020年12月开展免费乳腺癌筛查项目的检查数据,分析二维b超检查的检出率,比较两年间乳腺癌筛查趋势。结果:我院2019年1月-2020年12月接受免费乳腺癌筛查的女性2518例,进行临床乳腺检查和二维b超检查。2019年-2020年乳腺二维超声检查按照BI-RADS分级分为0-5级,其中0-3级的检查率为8.33%,4-5级的检查率为0.399%。病理学检查率由2019年的0.467%提高到了1.198%;两年共检出浸润性导管癌2例。2019年浸润性导管癌检出率0.718%(1/1393),2020年浸润性导管癌检出率0.889%(1/1125)(X2=0.314,P>0.05)。两年检出率上升趋势不明显。 结论:临床乳腺癌筛查中使用二维b超检查能有效筛查出乳腺癌及相关乳腺疾病,为广大女性普及乳腺癌预防知识,提高女性乳腺癌筛查意识,提供了有效途径,有效做到了妇女乳腺癌筛查应检尽检,早发现早治疗。

Importance of Percutaneous Radiofrequency Ablation for Recurrent Hepatocellular Carcinoma

Objective: To study the importance of percutaneous radiofrequency ablation (PRFA) guided by ultrasound for inoperable recurrent hepatocellular carcinoma.Methods: Forty-seven patients with inoperable recurrent hepatocellular carcinoma underwent percutaneous radiofrequency ablation (PRFA) under ultrasond between October 1999 and July 2001. Twenty-four patients had single recurrent tumor and 23 patients had multiple lesions. Twelve patients had single lesion with less than 3.5 cm in diameter. All patients were followed up to examine the value of AFP, MRI or CT after PRFA. Kaplan-Meier estimation was used to analyze the survival rate.Results: The 1-, 2- and 3-year survival rate in single lesion group was 65.2%, 37.5% and 37.5% respectively. The survival rate of 1 and 2 years was 41.7% and 19.5% in the multiple lesions group. The 1-, 2-and 3-year survival rate in single lesion groups with less than 3.5 cm in diameter was 83.3%, 51.4% and 51.4% respectively.Conclusion: PRFA is one of the important comprehensive methods for recurrent hepatocellular carcinoma. According to the size, number and recurrent time, PRFA can be performed separately or combined with transcatheter arterial chemoembolization for inoperable recurrent hepatocellular carcinoma. This method can control the recurrence and increase the survival rate effectively. Key words recurrence - hepatocellular cacinoma - radiofrequency ablation

Lipopolysaccharide-induced cerebral inflammatory damage and the therapeutic effect of platelet activating factor receptor antoganist

Objective To investigate lipopolysaccharide （LPS） induced acute cerebral inflammatory damage and the therapeutic effect of ginkgolide B （BN52021）. Methods Thirty Sprague-Dawley rats were randomly divided into 3 groups （n = 10 for each group）： Control group, Model group and Treatment group （treated with BN52021）. LPS were injected into the fourth ventricle of rat to make a neuroinflammatory murine model. Morris water maze was used to detect the learning and memory ability of rats; changes of synapse number and subcellular ultrastructures were observed under a transmission electron microscope; OX-42 positive microglia in the brain was detected by immunohistochemical method. Results The average escape latency in the Treatment group were significantly shortened than that in the Model group; and the percentage of swimming distance traveled in platform quadrant accounting for total distance increased markedly. The rough endoplasmic reticulum and polyribosomes in the Treatment group were more than that in the Model group, but the number of synapses seemed to have no obvious change. The number of OX-42 positive microglia in the Treatment group decreased markedly than that in the Model group, and the grey density of OX-42-positive cells increased significantly. Conclusion LPS can induce inflammatory damages to the brain, but the damage could be antagonized by BN52021. Platelet activating factor receptor antagonist may offer an effective therapy for neurodegeneration diseases.

Review of dynamic contrast-enhanced ultrasound guidance in ablation therapy for hepatocellular carcinoma

Local ablative techniques-percutaneous ethanol injection, microwave coagulation therapy and radiofrequency ablation (RFA)-have been developed to treat unresectable hepatocellular carcinoma (HCC). The success rate of percutaneous ablation therapy for HCC depends on correct targeting of the tumor via an imaging technique. However, probe insertion often is not completely accurate for small HCC nodules, which are poorly def ined on conventional B-mode ultrasound (US) alone. Thus, multiple sessions of ablation therapy are frequently required in diffi cult cases. By means of two breakthroughs in US technology, harmonic imaging and the development of second-generation contrast agents, dynamic contrast-enhanced harmonic US imaging with an intravenous contrast agent can depict tumor vascularity sensitively and accurately, and is able to evaluate small hypervascular HCCs even when B-mode US cannot adequately characterize the tumors. Therefore, dynamic contrast-enhanced US can facilitate RFA electrode placement in hypervascular HCC, which is poorly depicted by B-mode US. The use of dynamic contrast-enhanced US guidance in ablation therapy for liver cancer is an effi cient approach. Here, we present an overview of the current status of dynamic contrast-enhanced US-guided ablation therapy, and summarize the current indications and outcomes of reported clinical use in comparison with that of other modalities.

Efficacy of intraductal ultrasonography in the diagnosis of non-opaque choledocholith

AIM: To evaluate the efficacy of intraductal ultrasonography (IDUS) in the diagnosis of non-opaque, common bile duct stones. METHODS: A total of 183 patients (102 males, mean age 73 years; 81 females, mean age 70 years) with suspected common bile duct stones diagnosed through abdominal computed tomography (CT), magnetic resonance imaging (MRI), and abdominal Type-B ultrasound were included in the study. The diagnosis was confirmed through endoscopic retrograde cholangiopancreatography (ERCP) followed by IDUS. RESULTS: A total of 183 patients with suspected common bile duct (CBD) stones were included in the study as follows: 36 patients with high-density CBD stones, 68 patients with sand-like stones, 44 patients with low-density stones, 21 patients with ampullary cancer, and 14 patients with pancreatic cancer. Conventional imaging revealed 124 cases of choledochectasia, and only 36 cases of suspected CBD stones; ERCP revealed 145 cases of CBD stones with three missed diagnoses. IDUS revealed 148 cases of CBD stones, 21 cases of ampullary tumors, and 14 cases of pancreatic cancer. CONCLUSION: IDUS was more effective in the diagnosis of bile duct stones than ERCP, upper abdominal CT or upper abdominal MRI.

Quasispecies dynamics in main core epitopes of hepatitis B virus by ultra-deep-pyrosequencing

AIM:To investigate the variability of the main immunodominant motifs of hepatitis B virus(HBV) core gene by ultra-deep-pyrosequencing(UDPS).METHODS:Four samples(2 genotype A and 2 genotype D) from 4 treatment-na ve patients were assessed for baseline variability.Two additional samples from one patient(patient 4,genotype D) were selected for analysis:one sample corresponded to a 36-mo treatment-free period from baseline and the other to the time of viral breakthrough after 18 mo of lamivudine treatment.The HBV region analyzed covered amino acids 40 to 95 of the core gene,and included the two main epitopic regions,Th50-69 and B74-84.UDPS was carried out in the Genome Sequencer FLX system(454 Life Sciences,Roche).After computer filtering of UDPS data based on a Poisson statistical model,122 813 sequences were analyzed.The most conserved position detected by UDPS was analyzed by site-directed mutagenesis and evaluated in cell culture.RESULTS:Positions with highest variability rates were mainly located in the main core epitopes,confirming their role as immune-stimulating regions.In addition,the distribution of variability showed a relationship with HBV genotype.Patient 1(genotype A) presented the lowest variability rates and patient 2(genotype A) had 3 codons with variability higher than 1%.Patient 3 and 4(both genotype D) presented 5 and 8 codons with variability higher than 1%,respectively.The median baseline frequencies showed that genotype A samples had higher variability in epitopic positions than in the other positions analyzed,approaching significance(P = 0.07,sample 1 and P = 0.05,sample 2).In contrast,there were no significant differences in variability between the epitopic and other positions in genotype D cases.Interestingly,patient 1 presented a completely mutated motif from amino acid 64 to 67(E 64 LMT 67),which is commonly recognized by T helper cells.Additionally,the variability observed in all 4 patients was particularly associated with the E 64 LMT 67 motif.Codons 78 and 79 were highly conserved in all samples,in keeping with their involvement in the interaction between the HBV virion capsid and the surface antigens(HBsAg).Of note,codon 76 was even more conserved than codons 78 and 79,suggesting a possible role in HBsAg interactions or even in hepatitis B e antigen conformation.Sequential analysis of samples from patient 4(genotype D) illustrated the dynamism of the HBV quasispecies,with strong selection of one minor baseline variant coinciding with a decrease in core variability during the treatment-free and lamivudinetreated period.The drop in variability seemed to result from a "steady state" situation of the HBV quasispecies after selection of the variant with greatest fitness.CONCLUSION:Host immune pressure seems to be the main cause of HBV core evolution.UDPS analysis is a useful technique for studying viral quasispecies.

Clinical significance of magnetic resonance cholangiopancreatography utilizing half-Fourier acquisition single-shot fast spin-echo in diagnosing bile duct diseases

Objective: To investigate the clinical significance of magnetic resonance cholangiopancreatography (MRCP) utilizing half-Fourier acquisition single-shot fast spin-echo (HASTE) in the diagnosis of bile duct diseases. Methods: Forty-three patients with obstructive jaundice and 4 without were enrolled in this study. The underlying diseases included bile duct calculi ( 13 cases) , chronic cholangitis ( 14 cases) malignant tumors (18 cases) and congenital biliary cysts (2 cases). All patients underwent examinations with magnetic resonance imaging (MRI) and MRCP, and 39 were also examined with B-type ultrasonography, 33 with CT and 25 with ERCP and PTC. Three-dimensional image reconstruction was performed using volume-rendered technique ( VRE) on the basis of the data obtained by MRCP. Results: The biliary calculi were displayed as circular filling defects in MRCP images, with the proximal end of dilated bile duct taking the form of the mouth of a cup. The bile duct of patients with chronic cholangitis showed distal end dilation and thinner proximal end without discontinuity. Interception of the bile ducts was most frequent (72. 2% ) in cases of malignant bile duct obstruction, in which the ducts may also be mastoid or resembling rat tails. 72. 2% of the cases had severe dilation of the bile ducts, which occur in only 16. 0% of the benign cases, with significant difference between them (P <0. 01) . In images of intrahepatic biliary cyst, intrahepatic duct dilated in the shape of a bursa in connection with the duct. By MRCP, 20 malignant obstructions of the bile ducts were identified with 2 misdiagnoses, and in 25 cases of benign obstructions identified by MRCP, only 1 misdiagnoses occurred. Thus MRCP had the sensitivity, specificity and accuracy of 90.0% , 96.3% and 93.6% respectively in discriminating benign and malignant diseases of the bile ducts, showing a total diagnostic accuracy of 94. 0% that was similar to that of ERCP (92.0% ) but significantly higher than those of both CT (75. 0% ) and B-type ultrasonic examination (74. 0% ). Conclusion: In diagnosing obstructive jaundice, HASTE MRCP is similar to ERCP but better than CT and B-type ultrasonography , with the merits of fast imaging and high resolution as an ideal sequence for MRCP imaging.

Electro-acupuncture Treatment for the Upper Segment Ureterolithiasis Under B-Ultrasonography

In order to explore the effects of the local strong stimulation generated by electro-acupuncture for treatment of the upper segment ureterolithiasis,a controlled study was carded out among the treatment group (electro-acupuncture with strong stimulation),the control group Ⅰ(medication) and the control group Ⅱ (conventional acupuncture).The results showed that the differences in the cure rate and the total effective rate between the treatment group and the two control groups were significant in statistical analysis (P<0.05 and P<0.01 respectively).This indicates that better therapeutic effects can be obtained by the local strong stimulation generated by electro-acupuncture for treatment of the upper segment ureterolithiasis.

Damage characteristics of thermally treated granite under uniaxial compression: Insights from active and passive ultrasonic techniques

To explore the effects of thermal treatment on cracking processes in granite, granite samples were thermally treated at 25-400 ℃ and then loaded under uniaxial compression. Active ultrasonic testing and passive acoustic emission(AE) monitoring were combined to monitor the damage characteristics of the samples. The uniaxial compression strength(UCS) of the sample treated at 200 ℃ shows no apparent change compared with that of the nonheated sample, while the UCS increases at 300 °C and decreases at 400 ℃. As the temperature increases from 25 to 400 ℃, the initial P-wave velocity(Vp) decreases gradually from 4909 to 3823 m/s, and the initial Vpanisotropy ε increases slightly from 0.03 to 0.09. As the axial stress increases, ε increases rapidly in the crack closure stage and unstable cracking stage. The attenuation of ultrasonic amplitude spectra also shows an obvious anisotropy. Besides, the main location magnitude of AE events decreases after thermal treatment, and low-frequency AE events and high-amplitude AE events increasingly occur. However, there is insufficient evidence that the treatment temperature below 400 ℃ has a significant effect on the temporal characteristics, source locations, and b-values of AE.

Non-alcoholic fatty liver disease and metabolic syndrome in obese children

I read with great interest the article of Fu et al who investigated whether non-alcoholic fatty liver disease(NAFLD)is an early mediator for prediction of metabolic syndrome,and whether liver B-ultrasound could be used for its diagnosis,in a study involving 861 obese children(6-16 years old).In this study,it was reported that NAFLD is not only a liver disease,but also an early mediator that reflects metabolic disorder,and that liver B-ultrasound can be a useful tool for metabolic syndrome(MS)screening.The authors reported that NAFLD and MS were present in 68.18%and 25.67%of obese children,respectively.Moreover,they observed that the prevalence of MS in NAFLD children was 37.64%,which was much higher than that in the non-NAFLD group.Criteria analogous to those of the Adult Treatment PanelⅢdefinition for MS were used for children in this study.The reported prevalence data on MS in the young has varied markedly,in large part because of disagreement among the variously proposed definitions of MS.Therefore,in my opinion,a study aiming to assess the association between MS components and NAFLD in obese children has to take into account a simple,easy-to-apply clinical definition proposed by the international diabetes federation for MS.Interpretation of the results of the Fu et al study are limited byanother major caveat:that the diagnosis or exclusion of NAFLD was based on liver enzymes and ultrasound imaging,but was not confirmed by liver biopsy.Indeed,it is known that liver enzymes may be within the reference interval in up to 70%of patients with diagnosed NAFLD and that the full histopathological spectrum of NAFLD may be present in patients with normal liver enzymes,which therefore cannot be reliably used to exclude the presence of NAFLD.

Application Analysis of multimedia technology in the B-learning pedagogy

With the rapid development of modern information technology, in order to meet requirements of the new situation and new technologies, today＇ s teaching model has undergone a qualitative change. New teaching model are an entirely new challenge for health professional colleges, the college teachers and students. The Once chalk teaching is replaced by multimedia teaching, which is gradually popular in the country, including schools, tertiary institutions. But in recent years we have gradually discovered the shortcomings of multimedia teaching and thereby created a new hybrid teaching model B-Learning teaching. Multimedia technology effectively combining with the B-learning teaching model, will remove multimedia technology weaknesses, and better play their strengths in teaching.

B→ X8γ, X8l＋l- Decays and Constraints on Mass Insertion Parameters in MSSM

In this paper, we study the upper bounds on the mass insertion parameters （δAB^q）ij in the minimal super symmetric standard model. We found that the information from the measured branching ratio of B→ X8γ, X8l＋l- decay can help us to improve the upper bounds on the mass insertions parameters （δAB^u,d）3j,i3 Some regions allowed by the data of Br（B→ X8γ） are excluded by the requirement of an SM-like C7γ （rnb） imposedby the data of Br（B→ X8γ, X8l＋l- ）.

Double Charm Decays of B Mesons in mSUGRA Model

Based on the low energy effective Hamiltonian with naive factorization, we calculate the branching ratios （BRs） and CP asymmetries （CPAs） for the twenty three double charm decays B/B8 → D（＊）D（＊） in both the standard （s） （s） model （SM） and the minimal supergravity （mSUGRA） model. Within the considered parameter space, we find that （a） the theoretical predictions for the BRs, CPAs and the polarization fractions in the SM and the mSUGRA model are all consistent with the currently available data within ±2σ errors; （b） For all the considered decays, the supersymmetric contributions in the mSUGRA model are very small, less than 7% numerically. It may be difficult to observe so small SUSY contributions even at LHC.

An efficient quadrature demodulator for medical ultrasound imaging

Quadrature demodulation is used in medical ultrasound imaging to derive the envelope and instantaneous phase of the received radio-frequency(RF) signal.In quadrature demodulation,RF signal is multiplied with the sine and cosine wave reference signal and then low-pass filtered to produce the base-band complex signal,which has high computational complexity.In this paper,we propose an efficient quadrature demodulation method for B-mode and color flow imaging,in which the RF signal is demodulated by a pair of finite impulse response filters without mixing with the reference signal,to reduce the computational complexity.The proposed method was evaluated with simulation and in vivo experiments.From the simulation results,the proposed quadrature demodulation method produced similar normalized residual sum of squares(NRSS) and velocity profile compared with the conventional quadrature demodulation method.In the in vivo color flow imaging experiments,the time of the demodulation process was 5.66 ms and 3.36 ms,for the conventional method and the proposed method,respectively.These results indicated that the proposed method can maintain the performance of quadrature demodulation while reducing computational complexity.

DIAGNOSIS AND TREATMENT OF PHEOCHROMOCYTOMAS IN URINARY BLADDER

Objective To investigate the diagnosis and treatment of pheochromocytomas in urinary bladder and review relative literatures. Methods The clinical data of 6 cases of bladder pheochromocytoma were retrospectively analyzed. Bladder submucosal mass was detected by B-ultrasound in 6 cases, computerized tomography （CT） in 4, and cystoscopy in 3. All patients were treated with surgical operation. Results Two patients showed obvious fluctuation of blood pressure during operation. All patients were pathologically diagnosed as pheochromocytoma postoperatively. Five patients were followed up （from 3 months to 7 years） , and their blood pressure returned to normal. No patient had relapse and malignancy. Conclusion Typical hypertension during urination and hematuria constitute the chief symptoms of bladder pheochromocytoma. B-ultrasound, CT, and cystoscopy are the main methods for the localization of the lesions. Partial cystectomy or excision of the tumor is the preferred management and postoperative long-term follow-up is necessary.