The development of a room temperature electron cyclotron resonance ion source (Lanzhou electron cyclotron resonance ion source No. 4) with evaporative cooling technology at Institute of Modern Physics

LECR4 (Lanzhou electron cyclotron resonance ion source No. 4) has been successfully constructed at IMP and has also been connected with the Low Energy Beam Transport (LEBT) and Radio Frequency Quadrupole (RFQ) systems. These source magnet coils are cooled through evaporative cooling technology, which is the first attempt with an ECR ion source in the world. The maximum mirror field is 2.5 T (with iron plug) and the effective plasma chamber volume is 1.2 l. It was designed to be operated at 18 GHz and aimed to produce intense multiple charge state heavy ion beams for the linear injector project SSC-Linac at IMP. In February 2014, the first analyzed beam at 18 GHz was extracted. During about three months' commissioning, some outstanding results have been achieved, such as 1.97 emA of O(6+), 1.7 emA of Ar(8+), 1.07 emA of Ar(9+), and 118 euA of Bi(28+). The source has also successfully delivered O(5+) and Ar(8+) ion beams for RFQ commissioning in April 2014. This paper will give a brief overview of the design of LECR4. Then, the latest results of this source at 18 GHz will be presented.

Using SNP array to identify aneuploidy and segmental imbalance in translocation carriers

Translocation is one of the more common structural rearrangements of chromosomes, with a prevalence of 0.2%. The two most common types of chromosomal translocations, Robertsonian and reciprocal, usually result in no obvious phenotypic abnormalities when balanced. However, these are still associated with reproductive risks, such as infertility, spontaneous abortion and the delivery of babies with mental retardation or developmental delay.

In recent years, array-based whole-genome amplification (WGA) technologies, including microarray comparative genomic hybridization (array CGH; aCGH) and single-nucleotide polymorphism (SNP) micro-arrays, have enabled the screening of every chromosome for whole-chromosome aneuploidy and segmental imbalance. These techniques have been shown to have clinical application for translocation carriers. Promising studies have indicated that array-based PGD of translocation carriers can lead to transfer pregnancy rates of 45–70% [2].

In addition to genetic testing techniques, the embryo biopsy stage (polar body, cleavage embryo or blastocyst) and the mode of embryo transfer (fresh or frozen embryos) can affect the outcome of PGD. It is now generally recommended that blastomere biopsy should be replaced by blastocyst biopsy to avoid a high mosaic rate and biopsy-related damage to cleavage-stage embryos, which might affect embryo development. However, more clinical data are required to confirm that the technique of SNP array-based PGD (SNP-PGD) combined with trophectoderm (TE) biopsy and frozen embryo transfer (FET) is superior to traditional FISH-PGD combined with Day 3 (D3) blastomere biopsy and fresh embryo transfer.

Clinical effectiveness of neoadjuvant chemotherapy in advanced gastric cancer: an updated meta-analysis of randomized controlled trials

AIMS

To assess the efficacy and safety of neoadjuvant chemotherapy (NAC) for advanced gastric cancer (AGC).

METHODS

By searching electronic databases (PubMed, Embase, Cochrane Library) and ASCO proceedings from 1990 to 2012, all randomized controlled trials (RCTs) which compared the effect of NAC-combined surgery versus surgery alone in AGC were included. All calculations and statistical tests were performed using RevMan 5.0 software.

RESULTS

12 RCTs with a total of 1820 patients were included. All patients had locally advanced but resectable gastric cancer and received NAC. NAC can slightly improve the survival rate (OR = 1.32, 95% confidence interval (CI): 1.07-1.64, P = 0.01), with little or no significant benefits in subgroup analyses between either different population or regimens. NAC can significantly improve the 3-year progression-free survival (PFS) (OR: 1.85, 95% CI: 1.39-2.46, p < 0.0001), tumor down-staging rate (OR: 1.71, 95% CI: 1.26, 2.33, p = 0.0006) and R0 resection rate (OR: 1.38, 95% CI: 1.08-1.78, P = 0.01) of patients with AGC. There was no difference between the two arms, in terms of relapse rates (OR: 1.03, 95% CI: 0.60-1.78, p = 0.92), operative complications (OR: 1.20, 95% CI: 0.90-1.58, p = 0.21), perioperative mortality (OR: 1.14, 95% CI: 0.64-2.05, p = 0.65) and grade 3/4 adverse effects: gastrointestinal problem (OR: 0.57, 95% CI: 0.25-1.30, p = 0.18), leukopenia (OR: 0.88, 95% CI: 0.41-1.91, p = 0.75), thrombocytopenia (OR: 1.27, 95% CI: 0.27-5.93, p = 0.76).

CONCLUSION

NAC is effective and safe. However, further prospective multi-national and multi-center RCTs are still needed in order to investigate the long-term oncological and functional outcomes to define the clinical benefits of NAC and the most effective strategies for AGC.

Application of evaporative cooling technology in super-high power density magnet

Evaporative cooling technology utilizes phase-change heat transfer mode to achieve the cooling for heating equipment. The heat transfer capacity of evaporative cooling technology is far more than air or water cooling technology. The Electron Cyclotron Resonance ion source magnet is a typical super-high power density magnet, and the evaporative cooling technology is an ideal cooling method for the coils of magnet. In this paper we show the structure and process of coils and the special design of flow channels of coolant for an experiment magnet model. Additionally, the heat transfer circulation is presented and analyzed. By the finite element method, the flow channels are optimized to rationally allocate coolant and to reduce the temperature of coils. For the experiment model, the current density of copper wire of coils is 19 A/mm(2), and the coil-windows current density is larger than 12 A/mm(2). The max temperature of coils is below 80 °C, and the total heat is about 200 kW.

Progress of a room temperature electron cyclotron resonance ion source using evaporative cooling technology at Institute of Modern Physics

A new room temperature ECR ion source, Lanzhou Electron Cyclotron Resonance ion source No. 4 (LECR4, previously named DRAGON), is under intense construction at Institute of Modern Physics. LECR4 is designed to operate with 18 GHz microwave frequency. The maximum axial magnetic fields are 2.3 T at injection and 1.3 T at extraction, and the radial field at the plasma chamber wall of 76 mm inner diameter is 1.0-1.2 T. One of the unique features for LECR4 is that its axial solenoids are winded with solid square copper wires which are immersed in a kind of special evaporative cooling medium for cooling purpose. Till now, a prototype of the cooling system has been successfully constructed and tested, which has demonstrated that the cooling efficiency of the designed system could meet the requirements of LECR4 under the routine operation conditions. All the main components of the ion source have been completed. Assembly and commissioning is ongoing. The latest developments and test results will be presented in this paper.

Development of DRAGON electron cyclotron resonance ion source at Institute of Modern Physics

A new room temperature electron cyclotron resonance (ECR) ion source, DRAGON, is under construction at IMP. DRAGON is designed to operate at microwaves of frequencies of 14.5-18 GHz. Its axial solenoid coils are cooled with evaporative medium to provide an axial magnetic mirror field of 2.5 T at the injection and 1.4 T at the extraction, respectively. In comparison to other conventional room temperature ECR ion sources, DRAGON has so far the largest bore plasma chamber of inner diameter of 126 mm with maximum radial fields of 1.4-1.5 T produced by a non-Halbach permanent sextupole magnet.

Studies on anti-tumour activities of pseudolaric acid-B (PLAB) and its mechanism of action

Pseudolaric acid-B (PLAB), a diterpene acid, was isolated from the root and trunk barks of Pseudolarix kaempferi. It showed antifungal and anti-fertility effects as well as cytotoxic activities in previous studies. The present study investigates cytotoxic activity on cultured human cancer cells, inhibition on the growth of transplantable tumours in mice and the mechanism of these actions. The experimental results showed that PLAB had potent cytotoxic effects on cancer cells derived from different tissues. MTT assay showed that its IC50 towards these tumour cells was 0.17 to 5.20 micromol/L, and towards one normal human kidney proximal tubular epithelial cell (HKC) was 5.77 micromol/L. Furthermore, the results of cell growth curve and colony formation of cancer cells matched the above results. The results in vivo demonstrated that PLAB significantly inhibited the growth of transplantable tumours, such as Lewis lung cancer and hepatocarcinoma 22 (H22) in mice. The inhibitory rate to H22 was 14.4% and 40.1%, and to Lewis lung cancer reached 39.1% and 47.0%, when PLAB was given by intraperitoneal injection (i.p.) at a dose of 30 mg/kg/day and 60 mg/kg/day for 10 days, respectively. It is suggested that PLAB also showed obvious anticancer activity in vivo. Inducing apoptosis by PLAB in HeLa cells was assessed by various morphological and biochemical characteristics, including cell shrinkage, chromatin condensation, membrane blebbing, formation of apoptotic bodies, and internucleosomal DNA fragmentation. A typical 'sub-G1 peak' was also checked through flow cytometry. These results were accompanied by up-regulating P53, down-regulating Bcl-2 and activating Caspase-3, which was revealed by Western blotting. PLAB also caused cell cycle arrest to G2/M phase in a dose-dependent manner. The experiments suggest that PLAB is a new potent anti-tumour agent.

Secular trends in dietary macronutrient intake in Minneapolis-St, Paul, Minnesota, 1980-1992

Trends in dietary macronutrient intake were evaluated in population-based surveys conducted in adults aged 25-74 years in 1980-1982, 1985-1987, and 1990-1992 in the seven-county Minneapolis-St. Paul metropolitan area. A 24-hour dietary recall (n = 6,499) was completed by a random 50% sample. The authors obtained energy intake for each macronutrient (protein, carbohydrate, fat, saturated fat, monounsaturated fat, polyunsaturated fat, and alcohol). Tine trends for percentage of total energy were analyzed using a generalized linear mixed model. While energy intake remained stable over time, macronutrient composition changed substantially. In 1980-1982, the caloric distribution for men comprised 15.8% protein, 39.4% fat, 40.9% carbohydrate, and 3.9% alcohol; similar findings were observed in women (15.7% protein, 38.9% fat, 43% carbohydrate, and 2.4% alcohol). From 1980 to 1992, total fat intake decreased 4.7% in men and 4.9% in women (p < 0.001). The decline was greatest for monounsaturated fat, although saturated and polyunsaturated fat intake also fell. During this same period, carbohydrate intake increased 5.7% and 5.8% in men and women, respectively (p < 0.001). Alcohol intake decreased in men and women (p < 0.01), while protein intake remained stable. In summary, the Minneapolis-St. Paul metropolitan area diet shifted substantially during the 1980s toward more carbohydrate and lower fat and alcohol intake.

Prediction and prevention of extreme neonatal hyperbilirubinemia in a mature health maintenance organization

OBJECTIVE

To investigate biological and health services predictors of extreme neonatal hyperbilirubinemia in a health maintenance organization.

DESIGN

Nested case-control study.

SETTING

Eleven Northern California Kaiser Permanente hospitals.

SUBJECTS

The cohort consisted of 51,387 newborns born at 36 weeks or later weighing 2000 g or more. Cases were newborns with peak total serum bilirubin levels greater than or equal to 428 micromol/L (> or =25 mg/dL) (n = 73). Controls were a random sample of newborns from the cohort with peak bilirubin levels less than 428 micromol/L (<25 mg/dL) (n = 423).

MEASUREMENTS

Review of medical records and telephone interviews.

RESULTS

Early jaundice was most strongly associated with case status (odds ratio [OR] = 7.3). After excluding subjects with early jaundice, the strongest predictors of hyperbilirubinemia were family history of jaundice in a newborn (OR = 6.0), exclusive breastfeeding (OR = 5.7), bruising (OR = 4.0), Asian race (OR = 3.5), cephalhematoma (OR = 3.3), maternal age of 25 years or older (OR = 3.1), and lower gestational age (OR = 0.6/week). These variables identified 61% of newborns as very low risk (about 1/4200). However, the risk in the remaining 39% was still low (1/370). More cases (79%) than controls (59%) had newborn length-of-stay and follow-up consistent with the American Academy of Pediatrics guidelines, but phototherapy use within 8 hours of the time that the guidelines recommend was uncommon in both cases (26%) and controls (33%). There were no apparent cases of kernicterus.

CONCLUSIONS

Prevention of extreme hyperbilirubinemia may require closer follow-up than is currently recommended by the American Academy of Pediatrics and more use of phototherapy than was observed in this study. To prevent extreme hyperbilirubinemia (> or =428 micromol/L [> or =25 mg/dL]) in 1 newborn, many newborns would need to receive these interventions.

Neonatal sepsis workups in infants >/=2000 grams at birth: A population-based study

BACKGROUND

Few data are available on the outcome of neonatal sepsis evaluations in an era when intrapartum antibiotic therapy is common.

METHODS

We identified all newborns weighing >/=2000 g at birth who were ever evaluated for suspected bacterial infection at 6 Kaiser Permanente hospitals between October 1995 and November 1996, reviewed their records and laboratory data, and tracked them to 1 week after discharge. We analyzed the relationship between key predictors and the presence of neonatal bacterial infection.

RESULTS

Among 18 299 newborns >/=2000 g without major congenital anomalies, 2785 (15.2%) were evaluated for sepsis with a complete blood count and/or blood culture. A total of 62 (2.2%) met criteria for proven, probable, or possible bacterial infection: 22 (.8%) had positive cultures and 40 (1.4%) had clinical evidence of bacterial infection. We tracked all but 10 infants (.4%) to 7 days postdischarge. There were 67 rehospitalizations (2.4%; 2 for group B streptococcus bacteremia). Among 1568 infants who did not receive intrapartum antibiotics, initial asymptomatic status was associated with decreased risk of infection (adjusted odds ratio [AOR]:.26; 95% confidence interval [CI]:.11-.63), while chorioamnionitis (AOR: 2. 40; 95% CI: 1.15-5.00), low absolute neutrophil count (AOR: 2.84; 95% CI: 1.50-5.38), and meconium-stained amniotic fluid (AOR: 2.23; 95% CI: 1.18-4.21) were associated with increased risk. Results were similar among 1217 infants who were treated, except that maternal chorioamnionitis was not significantly associated with neonatal infection.

CONCLUSIONS

The risk of bacterial infection in asymptomatic newborns is low. Evidence-based observation and treatment protocols could be defined based on a limited set of predictors: maternal fever, chorioamnionitis, initial neonatal examination, and absolute neutrophil count. Many missed opportunities for treating mothers and infants exist.

[Cibacron blue F3GA-attached 2 microns non-porous monodisperse silicas for affinity chromatography]

Non-porous monodisperse silica (NPS), 2 microns in diameter, was modified with 3-aminopropyltriethoxysilane for immobilization of Cibacron Blue F3GA (CB), a packing of NPS-ACB for affinity chromatography was obtained. Up to 2 mg of CB could be attached to 1 mL of NPS beads. There was no obvious leakage of dye from NPS-ACB. Oval was not retained by the column, while Lys was specifically adsorbed. The adsorption of Lys varied with pH values and ionic strengths. In addition, alpha-globulin could not be retained by the packing, while beta- and gamma-globulin could be adsorbed on the column. gamma-Globulin was able to be eluted by 20% 1,6-hexanediol and 1 mol/L KCl, while beta-globulin was not able to be eluted by the same eluent. The difference in affinity interaction could be used to separate the three globulins. Furthermore, the column could be used for separation and preparation of Lys from hen egg white. The chromatograms of Lys on non-porous silica diethylamine column (NPS-DEA) showed that retention time of one peak of the crude Lys prepared was in accordance with Lys's, so it could be said that NPS-ACB column can be used for preparation in a small scale.

[Histological study and stereologic analysis of membranous versus endochondral onlay bone grafts]

OBJECTIVE

The experimental study was to determine the differences in changes in the onlay bone grafts of different embryonic origin.

METHODS

The study was designed to compare the potential for appositional bone growth in membranous and endochondral onlay grafts in New-Zealand rabbits and a rhesus monkey. Results were assessed with volumetric measurement, histological examinations and stereologic analysis with double-fluorochrome labeling technique.

RESULTS

For the membranous and endochondral bone grafts, the volumetric retention rate was (78.4 +/- 3.5)% and (56.0 +/- 5.1)% respectively. The mineralization apposition rate (MAR) was (3.6 +/- 0.8) microns/d and (0.92 +/- 0.33) micron/d; the osteoid seam width (OSW) was (14.56 +/- 2.69) microns and (7.38 +/- 2.20) microns; the tetracycline uptake rate(TUA) was (91.22 +/- 2.69)% and (51.28 +/- 4.11)%, respectively.

CONCLUSION

1. It was found that the membranous bone graft maintained its volume to a significantly greater extent than the endochondral bone graft; 2. Membranous bone grafts exhibited higher survival rate and greater activity than endochondral bone grafts; 3. Different changes were also found in the two recipient sites. There was more powerful bone regenerative reaction in the recipient bed of the membranous bone graft than the endochondral one.

[Study of microsatellite instability of colotectal cancer and its clinical significance]

OBJECTIVE

To evaluate microsatellite instability (MI) of colorectal cancer in China.

METHOD

Replication error (RER) status was examined by using 6 microsatellite loci D2S123, D2S119, D13S160, D8S282, D3S1293 and D18S58. The loci were amplified by PCR technique. The PCR products were separated on denatured polyacrylamide gel and then silver stained.

RESULTS

Of the 60 cases of colorectal cancer studied, 20 (33.3%) showed MI, 11 cases (18.3%) were RER positive. In 11 RER-positive cases, 4(36.4%) had family history of malignant tumor, while only 8.2% had positive family history in RER-negative cases (P < 0.05). The RER-positive patients were younger, and their cancer occurred more frequently in the colon with invasive type of growth. There were more cancers in Dukes III and IV in the REF-positive patients. In 5 colorectal cancer cases associated with adenoma, MI was detectable in 4 adenomas.

CONCLUSION

MI phenotype might be present ubiquitously in sporadic colorectal cancers in China. Its frequency is comparable to that of other reports. MI is a relatively early molecular event in the genesis of colorectal cancers. RER is a useful sign of susceptibility to the development of colorectal cancer.

A physiological approach to surgical treatment of progressive early idiopathic scoliosis

The results of previous clinical and experimental studies have provided accumulated evidence for the role of rib asymmetry in the pathogenesis of idiopathic scoliosis (IS). Moreover, it has been shown that scoliosis induced in rabbits can be corrected by elongation or growth stimulation of ribs on the side of the convexity. Taking these observations into consideration, a 7-year-old girl with right convex thoracolumbar IS was operated upon by 2-cm shortening of three concave ribs. The preoperative coronal Cobb angle was 46 degrees and the sagittal angle was 55 degrees. Twenty-seven months after the operation the curves were reduced to 21 degrees and 35 degrees, or by 54 and 36%, respectively. It is concluded that new, easy to perform and harmless interventions on the ribs may have vast implications for the overall treatment of young patients with early progressive, thoracic, IS.

[Developments and applications of perfusion chromatography]

This review deals with the developments and applications of perfusion chromatography proposed recently by Afeyan and its related techniques. The review with 40 references involves characteristics, theories and applications of perfusion chromatography.

Rib-vertebral angle asymmetry in idiopathic, neuromuscular and experimentally induced scoliosis

The concave and convex rib-vertebral angle (RVA) at levels T2-T12 was measured on AP radiographs of 19 patients with right convex idiopathic thoracic scoliosis and 10 patients with major thoracic right convex neuromuscular scoliosis. The difference between the angles on the concave and the convex sides, the RVAD, was calculated. The RVAs were also measured on radiographs from three animal groups in which spinal curves had been induced experimentally in a variety of ways. Group 1 comprised 16 rabbits that had been subjected to selective electrostimulation of the latissimus dorsi, the erector spinae and the intercostal muscles. Group 2 comprised four dead rabbits whose spines had been subjected to manual bending. Group 3 comprised eight rabbits that had undergone mechanical elongation of one rib. In both the idiopathic and the neuromuscular group, the convex RVA was smaller than the concave RVA between levels T2 and T8, with a maximal difference between T4 to T5. From T9 to T12 the concave RVA was smaller than the convex. The RVA in relation to the scoliotic segment, i.e. the apex level of the curve and the two neighbouring vertebrae above and below this level, showed similar results. With increasing Cobb angle the RVADs increased linearly with the greatest difference at the second vertebra above the apex. In the three experimental groups the pattern of the RVADs between T6 to T12 was basically similar to the findings of the clinical study. From the results of these clinical and experimental studies, it is concluded that the typical pattern of the RVAs on the concave and convex sides seems to be independent of the underlying cause of the spinal curvature. It is likely that the RVADs result from a passive mechanical adaptation of the ribs to the lateral curvature of the spine.

The position of the aorta in relation to the vertebra in patients with idiopathic thoracic scoliosis

One CT-scan at the central part of the vertebral body of the apical vertebra of 32 patients with right convex thoracic idiopathic scoliosis and one CT-scan of either T8 or T9 of 22 normal subjects are included in this study. The position of the aorta in relation to the apical vertebra of the scoliotic patients and the corresponding vertebra of the normal subjects was determined at the horizontal plane. The mean lateral translation of the aorta in relation to the mid axis of the vertebral body increased from 19.7 +/- 4.3 mm in the normal group to 26.4 +/- 4.1 mm in the scoliotic group (p = 0.0001). In the normal group the aorta was located 41.7 +/- 8.6 mm in front of a perpendicular line to the mid axis of the vertebral body and in the scoliotic group this distance was reduced to 30.0 +/- 9.0 mm making the position of the aorta more posterior in the scoliotic group (p = 0.0001). This was in accordance with a decreased mean kyphosis-lordosis index from 0.53 +/- 0.06 in the normal group to 0.46 +/- 0.07 in the scoliotic group (p = 0.01). The position of the aorta, also expressed as the angle formed between the aorta and the vertebral body, the "aorto-vertebral angle", was increased from 24.4 degrees +/- 6.9 degrees in the normal group to 41.4 degrees +/- 8.4 degrees the scoliotic patients, (p = 0.0001). The aorto-vertebral angle did not change significantly with increasing Cobb angle (p = 0.26) but was positively correlated to the vertebral rotation (p = 0.0001). An estimation of the length of the intercostal arteries revealed a significantly greater R (right)/L (left) index in the scoliotic patients 1.18 +/- 0.11 than in the normal subjects 1.08 +/- 0.06 (p = 0.0003). It is concluded that the rotation and the anterior displacement of the vertebral body in scoliosis result in a deviation of the aorta along the left (concave) side of the vertebral body to a more posterior position relative to the vertebral body with a possible increased length of the intercostal artery on the right (convex) side.

The black fly Simulium vittatum trypsin gene: characterization of the 5'-upstream region and induction by the blood meal

The events leading to blood digestion in hematophagous insects are not well understood at the molecular level. Here we report on the characterization of a trypsin gene from the black fly Simulium vittatum. Southern blot analysis indicated that the S. vittatum genome contains at least two trypsin genes. Primer extension experiments identified two closely spaced transcription initiation sites, 3 bp apart. A genomic clone containing the trypsin gene was restriction mapped and the nucleotide sequence of the 5'-upstream region was determined. Several sequence elements were identified, including a consensus TATA box 35 nucleotides upstream from the transcription initiation site, a consensus arthropod initiator site at position -7, and two conserved sequence elements, 5'GGATTAA (position -77) and 5'TGTTTCCT (position -148). The latter two elements are present at comparable distances from the transcription initiation sites in black fly and mosquito trypsin genes. Significant amounts of trypsin mRNA were detected in guts of sugar-fed flies. Upon blood feeding, trypsin mRNA levels gradually increased to reach twice the initial abundance at 8 hr after blood ingestion. In contrast to other hematophagous insects, the induced mRNA level persists for a prolonged period of time (at least 48 hr) after blood ingestion. The results of this study provide information that may be useful for the expression of transgenes in insects of medical importance.

Gut-specific transcriptional regulatory elements of the carboxypeptidase gene are conserved between black flies and Drosophila

Millions of people die every year in the tropical world from diseases transmitted by hematophagous insects. Failure of conventional containment measures emphasizes the need for additional approaches, such as transformation of vector insects with genes that restrict vectorial capacity. The availability of an efficient promoter to drive foreign genes in transgenic insects is a necessary tool to test the feasibility of such approach. Here we characterize the putative promoter region of a black fly midgut carboxypeptidase gene and show that these sequences correctly direct the expression of a beta-glucuronidase reporter in Drosophila melanogaster. By histochemical staining and mRNA analysis, we found that the gene is expressed strongly and gut-specifically in the transgenic Drosophila. This gut-specific black fly carboxypeptidase promoter provides a valuable tool for the study of disease vectors.