[Effects of bariatric surgery on sex hormones in male patients with obesity].

Objective: To analyze and evaluate the differences in sex hormones after laparoscopic Roux-en-Y Gastric Bypass Surgery (LRYGB) and laparoscopic sleeve gastrectomy (LSG) in male patients with obesity. Methods: This study was a retrospective cohort study. The inclusion criteria were (1) male patients with obesity who met the surgical indications of the "Chinese Guidelines for Surgical Treatment of Obesity and Type 2 Diabetes" (2019 Edition); (2) patients with a body mass index (BMI) of ≥27.5 kg/m2 and obesity-related metabolic diseases, or patients with severe obesity and a BMI of ≥35 kg/m2; and (3) sex hormone levels checked 1 year after surgery. The exclusion criteria included (1) patients with endocrine diseases (thyrotoxicosis, hyperprolactinemia) and hypothalamic-pituitary lesions and (2) those with severe major organ dysfunction who could not tolerate anesthesia or surgery. According to the above criteria, the clinical data of male patients with obesity admitted to the Gastrointestinal Surgery/Bariatric Center of the First Affiliated Hospital of Jinan University from October 2017 to January 2020 were included. A total of 52 male patients with obesity were included in this study. The mean age, body weight, BMI, and total testosterone level were (29.3±10.2) years, (123.6±35.4) kg, (40.1±11.1) kg/m2, and 7.6 (5.5, 9.1) nmol/L, respectively. Forty-five patients (86.5%) exhibited testosterone deficiency. Among all the patients, 29 underwent LSG (LSG group) and 23 underwent LRYGB surgery (LRYGB group). The main outcome measure was the change in sex hormone levels before and after bariatric surgery in all the patients. The secondary outcome measures were the comparison of changes in sex hormone levels before and after LSG and LRYGB. Results: Pearson correlation analysis showed that preoperative estradiol was positively correlated with waist circumference (R=0.299, P<0.05), hip circumference (R=0.326, P<0.05), and chest circumference (R=0.388, P<0.05). Testosterone was negatively correlated with BMI (R=-0.563, P<0.01), waist circumference (R=-0.521, P<0.01), hip circumference (R=-0.456, P<0.01), chest circumference (R=-0.600, P<0.01), and neck circumference (R=-0.547, P<0.01). One year following bariatric surgery, the serum testosterone (7.6 [5.5, 9.1] nmol/L vs. 13.6 [10.5, 15.4] nmol/L, Z=-5.910, P<0.001), follicle-stimulating hormone (4.7 [2.7, 5.3] IU/L vs. 6.5 [3.6, 7.8] IU/L, Z=-4.658, P<0.001), and progesterone (1.2 [0.4, 1.5] nmol/L vs. 1.9 [0.8, 1.3] nmol/L, Z=-2.542, P=0.011) levels were significantly higher in all the patients. Both estradiol (172.8 [115.6, 217.5] pmol/L vs. 138.3 [88.4, 168.1] pmol/L, Z=-2.828, P=0.005) and prolactin (11.4 [6.4, 14.6] mIU/L vs. 8.6 [4.8, 7.3] mIU/L, Z=-2.887, P=0.004) levels were decreased. In addition to prolactin levels in the LRYGB group, there were statistically significant differences in the levels of estradiol (P=0.030), follicle-stimulating hormone (P < 0.001), luteinizing hormone (P=0.033), progesterone (P=0.034), and testosterone (P<0.001) compared with their preoperative levels. In the LSG group, there were statistically significant differences in the levels of follicle-stimulating hormone (P=0.011), prolactin (P=0.023), and testosterone (P<0.001) compared with their preoperative levels. Conclusion: The degree of obesity in men was negatively correlated with testosterone levels. Both LRYGB and LSG can significantly improve sex hormone levels in male patients with obesity, and testosterone levels show a significant increase after surgery.

[Safety and feasibility of intrathoracic modified overlap esophagojejunostomy in laparoscopic radical resection of Siewert type â ¡ adenocarcinoma of esophagogastric junction].

Objective: The study aimed to investigate the safety and feasibility of intrathoracic modified overlap method in laparoscopic radical resection of Siewert type II adenocarcinoma of the esophagogastric junction (AEG). Methods: A descriptive case series study was conducted. The clinical data of 27 patients with Siewert type II AEG who underwent transthoracic single-port assisted laparoscopic total gastrectomy and intrathoracic modified overlap esophagojejunostomy in Guangdong Provincial Hospital of Chinese Medicine from May 2017 to December 2020 were retrospectively analyzed. The intrathoracic modified overlap esophagojejunostomy was performed as follows: (1) The Roux-en-Y loop was made; (2) The jejunum side was prepared extraperitoneal for overlap anastomosis; (3) The esophagus side was prepared intraperitoneal for overlap anastomosis; (4) The overlap esophagojejunostomy was performed; (5) The common outlet was closed after confirmation of anastomosis integrity without bleeding; (6) A thoracic drainage tube was inserted into the thoracic hole with the diaphragm incision closed. The intraoperative and postoperative results were reviewed. Results: All 27 patients were successfully operated, without mortality or conversion to laparotomy. The operative time, digestive tract reconstruction time and esophageal-jejunal anastomosis time were (327.5±102.0) minute, 50 (28-62) minute and (29.0±7.4) minute, respectively. The blood loss was 100 (20-150) ml. The postoperative time to flatus and postoperative hospital stay were (4.7±3.7) days and 9(6-73) days, respectively. Three patients (11.1%) developed postoperative grade III complications according to the Clavien-Dindo classification, including 1 case of anastomotic fistula with empyema, 1 case of pleural effusion and 1 case of pancreatic fistula, all of whom were cured by puncture drainage and anti-infective therapy. Conclusions: The intrathoracic modified overlap esophagojejunostomy is safe and feasible in laparoscopic radical resection of Siewert type II AEG.

[Efficacy observation of the caudal-medial approach combined with "page-turning" middle lymphadenectomy in the laparoscopic right hemicolectomy].

Objective: To investigate the safety and feasibility of caudal-medial approach combined with "page-turning" middle lymphadenectomy in the laparoscopic right hemicolectomy. Methods: A descriptive cohort study was conducted. Clinical data of 35 patients who underwent laparoscopic radical right hemicolectomy using caudal-medial approach combined with "page-turning" middle lymphadenectomy at Department of Gastrointestinal Surgery, Guangdong Hospital of Chinese Medicine from April 2018 to May 2020 were retrospectively analyzed. All operations were performed consecutively by the same surgeon. The caudal-medial approach was used to dissect the right Toldt's fascia and the anterior pancreaticoduodenal space in a caudal-to-cranial and medial-to-lateral manner guided by the duodenum. The "page-turning" middle lymphadenectomy was used to dissect the mesocolon along the superior mesenteric vein with ileocolic vein, Henle's trunk and pancreas exposed preferentially. Results: All the 35 patients completed the operation successfully, and there was no damage and bleeding of superior mesenteric vessels and their branches. The operative time was (186.9±46.2) minutes, and the blood loss was 50 (10-200) ml. The first time to flatus was (2.1±0.6) days, and the time to fluid intake was (2.5±0.8) days. The postoperative hospital stay was 6 (3-18) d. The overall morbidity of postoperative complication was 8.6% (3/35), including grade II in 1 cases (2.8%) and grade IIIa in 2 case (5.7%) according to the Clavien-Dindo grading standard. The total number of lymph node dissected was 30.2±5.6, and the positive lymph node was 0 (0-7). Tumor staging revealed 5 cases of stage I, 18 cases of stage II, 11 cases of stage III, and 1 case of stage IVA. In this study, the median follow-up time was 15 (4-29) months. One patient died due to cerebrovascular accident 12 months after surgery, and no tumor recurrence or metastasis was observed in all other patients. Conclusions: Laparoscopic radical right hemicolectomy using caudal-medial approach combined with "page-turning" middle lymphadenectomy is safe and feasible. The anterior pancreaticoduodenal space is preferentially mobilized, which reduces the difficulty of central vascular dissection.

[Comparison of clinical efficacy between bursa omentalis approach and medial-to-lateral approach in laparoscopic left hemicolectomy: a propensity score matching analysis].

Objective: Splenic flexure mobilization is technically difficult during the resection of left hemicolon cancer. This study aims to compare the safety and effectiveness between the bursa omentalis approach (BOA) and medial-to-lateral approach (MTLA) in laparoscopic radical resection of left-sided colon cancer. Methods: A retrospective cohort study was conducted. Inclusion criteria: (1) patients underwent radical resection of left hemicolon cancer; (2) the postoperative pathological result was adenocarcinoma; (3) patients aged 18-80 years old; (4) no liver, peritoneal or other distant metastasis. Exclusion criteria: (1) poor physical condition with serious heart, brain, lung, liver, kidney and hematopoietic system diseases; (2) unable to tolerate laparoscopic surgery; (3) history of other malignancies simultaneously, or multisource tumors; (4) emergency operation due to bleeding, obstruction, perforation, etc. Clinical data of 189 patients who underwent laparoscopic left hemicolectomy in the Guangdong Provincial Hospital of Chinese Medicine from 2014 to 2020 were retrospectively analyzed. According to surgical approaches, patients were divided into the BOA group (52 cases) and MTLA group (137 cases). The whole group of patients were matched by propensity score matching (PSM) according to the nearest neighbor matching method. The caliper value was 0.01. The matching variables included gender, age, American Society of Anesthesiologists (ASA) score, body mass index, tumor location and tumor stage. After PSM, 47 patients were included in the BOA group and MTLA group, respectively. There were no significant differences in baseline data between the two groups after PSM (all P>0.05). Paired t-test, paired rank sum test and paired Chi-square test were used to compare intraoperative and postoperative paramether between the two groups. Kaplan-Meier method was used to draw the survival curve, and log rank test was used for inter group comparison. When the two survival curves intersect, the two-stage method and restricted mean survival time (RMST) were further performed. Results: Both groups of patients successfully completed the operation without conversion to laparotomy or intraoperative death. No combined splenectomy or pancreatectomy were performed in the two groups. There were also no significant differences in intraoperative blood loss, number of harvested lymph nodes, time to the first flatus and the length of hospital stay between the two groups (all P>0.05). However, the median laparoscopic dissection time in the BOA group was shorter than that in the MTLA group, and the difference was statistically significant (median: 56 minutes vs. 65 minutes, P=0.032). No entry to posterior pancreatic space was recorded in the BOA group but wrong entry to posterior pancreatic space happened to 6.4% (3/47) of patients (body mass index >25 kg/m(2)) when dissecting left Toldt's fascia in the MTLA group. The 3-year disease-free survival rate in BOA group and MTLA group was 90.2% and 86.1%, respectively (P=0.909) and the 3-year overall survival rate was 85.6% and 94.4%, respectively (P=0.532). Conclusions: BOA is safe and feasible in laparoscopic left hemicolectomy, especially for inexperienced surgeons. For obese patients, BOA facilitates the entrance into the correct anatomical level and avoid entering the retropancreatic space.

[Five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph node dissection for Siewert type â ¡ adenocarcinoma of the esophagogastric junction].

Objective: Surgical operation is the main treatment for advanced adenocarcinoma of esophagogastric junction (AEG). Due to its special anatomic location and unique lymph node reflux mode, the surgical treatment of Siewert II AEG is controversial. Lower mediastinal lymph node dissection is one of the most controversial points and a standard technique has not yet been established. This study is aim to explore the safety and feasibility of five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph node dissection for Siewert type II AEG. Methods: A descriptive case series study was conducted. The intraoperative and postoperative data of 25 patients with Siewert type II AEG who underwent five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph node dissection in Guangdong Provincial Hospital of Traditional Chinese Medicine from January 2019 to April 2021 were retrospectively analyzed. Five-step maneuver was as follows: In the first step, the subcardiac sac was exposed; the right pulmonary ligament lymph nodes and the anterior thoracic paraaortic lymph nodes were dissected cranial to inferior pericardium, left to left edge of thoracic aorta. In the second step, the left diaphragm was opened, and a 12 mm trocar was placed through the 6-7 rib in the left anterior axillary line. The supra-diaphragmatic nodes were dissected through the thoracic operation hole. In the third step, the left inferior pulmonary ligament was severed. The anterior fascia of thoracic aorta was incised to join the anterior space of thoracic aorta formed in the first step and then the lymphatic tissue was dissected upward until the exposure of left inferior pulmonary vein. In the fourth step, the posterior pericardium was denuded retrogradely from ventral side to oral side to the level of left inferior pulmonary vein, right to right pleura, and then the right pulmonary ligament lymph nodes were completely removed. In the fifth step, the esophagus was denuded, and the esophagus was transected 5 cm above the tumor using a linear stapler to complete the dissection of lower thoracic paraesophageal lymph nodes. Results: Operations were successfully completed in 25 patients without conversion, intra-operative complication and perioperative death. Total gastrectomy was performed in 19 cases and proximal gastrectomy in 6 cases. The mean operative time was (268.7±85.6) minutes, the mean estimated blood loss was (90.4±44.2) ml, the mean time of lower mediastinal lymph node dissection was (38.6±10.3) minutes, and the mean harvested number of lower mediastinal lymph node was 5.9±2.9. The length of esophageal invasion was >2 cm in 7 cases and ≤ 2 cm in 18 cases. Eight patients (33.0%) had lower mediastinal lymph node metastasis, including 3 cases with esophageal invasion >2 cm and 5 cases with esophageal invasion ≤ 2 cm. The mean time to postoperative first flatus was (5.5±3.1) days. The average time of postoperative thoracic drainage was (5.9±2.9) days. The mean hospital stay was (9.7±3.1) days. Two patients (8.0%) developed postoperative grade IIIa complications according to the Clavien-Dindo classification, including 1 case of pancreatic fistula and 1 case of pleural effusion, both of whom were cured by puncture drainage. Conclusions: Five-step maneuver of transthoracic single-port assisted laparoscopic lower mediastinal lymph nodes dissection for Siewert type II AEG is safe and feasible. Which can ensure sufficient lower mediastinal lymph node dissection to the level of left inferior pulmonary vein.

[Safety and feasibility of laparoscopic double-flap technique in digestive tract reconstruction after proximal gastrectomy for esophagogastric junction tumors larger than 5 cm].

Objective: To investigate the safety and feasibility of laparoscopic double-flap technique (Kamikawa) in digestive tract reconstruction after proximal gastrectomy for esophagogastric junction (EGJ) leiomyoma and gastrointestinal stromal tumor (GIST) with the maximum diameter >5 cm. Methods: A descriptive case-series study was used to retrospectively analyze the data of patients with EGJ leiomyoma and GIST undergoing laparoscopic-assisted proximal gastrectomy and double-flap technique (Kamikawa) at the Department of Gastrointestinal Surgery, Guangdong Hospital of Traditional Chinese Medicine from September 2017 to March 2019. All the tumors invaded the cardia dentate line, and the maximum diameter was >5 cm. After the exclusion of patients requiring emergency surgery and complicating with severe cardiopulmonary diseases, a total of 4 patients, including 3 males and 1 female with age of 29-49 years, were included in this study. After laparoscopic-assisted proximal gastrectomy, the residual stomach was pulled out of the abdominal cavity and marked with methylene blue at the proximal end 3~4 cm from the anterior wall of the residual stomach in the shape of "H". The gastric wall plasma muscular layer was cut along the "H" shape, and the space between the submucosa and the muscular layer was separated to both sides along the longitudinal incision line to make the seromuscular flap. The residual stomach was put back into the abdominal cavity. Under laparoscopy, 4 stitches were intermittently sutured at the upside of "H" shape and 4-5 cm from the posterior wall of the esophageal stump. The stump of the esophagus was cut open, and the submucosa and mucosa were cut under the "H" shape to enter the gastric cavity. The posterior wall of the esophageal stump was sutured continuously with the gastric stump mucosa and submucosa under laparoscopy. The anterior wall of the esophageal stump was sutured continuously with the whole layer of the residual stomach. The anterior wall of the stomach was sutured to cover the esophagus. The anterior gastric muscle flap was sutured and embedded in the esophagus to complete the reconstruction of digestive tract. The morbidity of intraoperative complications and postoperative reflux esophagitis and anastomosis-related complications were observed. Results: All the 4 patients completed the operation successfully, and there was no conversion to laparotomy. The median operative time was 239 (192-261) minutes, the median Kamikawa anastomosis time was 149 (102-163) minutes, and the median intraoperative blood loss was 35 (20-200) ml. The abdominal drainage tube and gastric tube were removed, and the fluid diet was resumed on the first day after surgery in all the 4 patients. The median postoperative hospitalization time was 6 (6-8) days. Postoperative pathology revealed 3 leiomyomas and 1 GIST. There were no postoperative complications such as anastomotic leakage or stenosis, and no reflux symptoms were observed. The median follow-up time was 22 (11-29) months after the operation, and no reflux esophagitis occurred in any of the 4 patients by gastroscopy. Conclusion: For >5 cm EGJ leiomyoma or GIST, double-flap technique (Kamikawa) used for digestive tract reconstruction after proximal gastrectomy is safe and feasible.

Proteomics analysis of suckling mouse brain infected with attenuated rabies virus strain SRV9.

Rabies virus is an enveloped negative-stranded RNA virus belonging to the family Rhabdoviridae. It can be successfully controlled by vaccination however, there are still tens of thousands of deaths each year caused by rabies virus due to its mutations and complexity. A better understanding of the interaction between the rabies virus and the host might help solve this problem. Therefore, in this study, we used two-dimensional electrophoresis to investigate the protein expression of rabies virus-infected mice. This can help us to understand the impact of rabies virus on host protein expression during infection. For our experiment, two-dimensional electrophoresis was used to analyze the differential proteomics of the brain of 10- and 20-day-old suckling mice infected with attenuated rabies virus strain SRV9. The results showed that the expression levels of 10 protein spots had been up- or down-regulated at least 2-fold. Using MALDI-TOF-MS, we identified 8 differentially expressed proteins. We have identified proteins, namely hnRNP L, DPYSL3, NECAPs, and transaldolase that might be closely related to the susceptibility of SRV9 in suckling mice. Keywords: rabies virus; attenuated strain; suckling mouse; two-dimensional electrophoresis; proteomics.

The genetics of brown coat color and white spotting in domestic yaks (Bos grunniens).

Domestic yaks (Bos grunniens) exhibit two major coat color variations: a brown vs. wild-type black pigmentation and a white spotting vs. wild-type solid color pattern. The genetic basis for these variations in color and distribution remains largely unknown and may be complicated by a breeding history involving hybridization between yaks and cattle. Here, we investigated 92 domestic yaks from China using a candidate gene approach. Sequence variations in MC1R, PMEL and TYRP1 were surveyed in brown yaks; TYRP1 was unassociated with the coloration and excluded. Recessive mutations from MC1R, or p.Gln34*, p.Met73Leu and possibly p.Arg142Pro, are reported in bovids for the first time and accounted for approximately 40% of the brown yaks in this study. The remaining 60% of brown individuals correlated with a cattle-derived deletion mutation from PMEL (p.Leu18del) in a dominant manner. Degrees of white spotting found in yaks vary from color sidedness and white face, to completely white. After examining the candidate gene KIT, we suggest that color-sided and all-white yaks are caused by the serial translations of KIT (Cs6 or Cs29 ) as reported for cattle. The white-faced phenotype in yaks is associated with the KIT haplotype S(wf) . All KIT mutations underlying the serial phenotypes of white spotting in yaks are identical to those in cattle, indicating that cattle are the likely source of white spotting in yaks. Our results reveal the complex genetic origins of domestic yak coat color as either native in yaks through evolution and domestication or as introduced from cattle through interspecific hybridization.

Keloid microRNA expression analysis and the influence of miR-199a-5p on the proliferation of keloid fibroblasts.

The purpose of this study was to identify microRNAs (miRNAs) involved in keloid formation and determine their influence on the proliferation of keloid fibroblasts (KFs). Eight specimens each of resected keloid tissue and normal skin tissue were collected. miRNAs that are differentially expressed in keloid tissue and normal skin were detected using an miRNA microarray and verified by quantitative real-time polymerase chain reaction (RT-PCR). Seventeen differentially expressed miRNAs, including miR-199a-5p, were identified by microarray hybridization. qRT-PCR analysis confirmed the decrease in miR-199a-5p expression in keloid vs normal tissue that was detected by the microarray analysis. Mimics of differentially expressed miRNAs were then transfected into a KF cell line, and the effect of miRNA overexpression on the proliferation of KFs was assayed using the EdU assay. Compared with mock-transfected cells, KFs transfected with a miR-199a-5p mimic showed significantly lower cell proliferation and an altered cell cycle, with cells having significantly longer S and G2/M phases. The significantly lower expression of miRNA-199a-5p in keloids likely influences the cell cycle of KFs and restrains their proliferation, suggesting that miR-199a-5p probably plays a role in the regulation of KF proliferation.

A theoretical study of electronic and optical properties of SiC nanowires and their quantum confinement effects.

We have performed a theoretical study of silicon carbide nanowires (SiCNWs) within the framework of first-principles calculations by incorporating the size effect and hydrogen terminated surface. Specifically, the variation of the energy gap and optical absorption spectra for hydrogen passivated SiCNWs and pristine wires are examined with respect to the wire diameter. All the [001]-orientated SiCNWs derived from the parent zinc-blende (3C) exhibit semiconducting behavior. Our study demonstrates that the saturated 3C-SiCNWs grown along the [001] direction with larger wire sizes are energetically more favorable than the wires with a smaller diameter. Additionally, the energy gaps are reduced with the increment of wire size because of the quantum-confinement effects. The unsaturated SiCNWs possess smaller band gaps than those of saturated ones when the Si- and C-dangling bonds are passivated by hydrogen atoms. Interestingly, the surface terminated by hydrogen atoms substantially alters the onset of absorption as well as the spectrum behavior at upper energies. Moreover, some pronounced fine structures in the absorption peak are conspicuous at the lower energy region of hydrogen saturated SiCNWs as the wire size increases. We find that the distributions of the highest occupied molecular orbitals and the lowest unoccupied molecular orbitals are uniform along the wire axis, which reveals that the SiCNWs are exceptional candidates in producing nano-optoelectronic devices.

Antigenicity and functional properties of ß-lactoglobulin conjugated with fructo-oligosaccharides in relation to conformational changes.

Bovine ß-lactoglobulin (ß-LG) was conjugated with fructo-oligosaccharides (FOS) by Maillard reaction to investigate the relationship among antigenicity, functional properties, and conformational changes of ß-LG. When comparing the antigenicity of ß-LG conjugated with FOS at different ratios, the lowest antigenicity of ß-LG was observed at a ratio of 1:4, which was about 7 times lower than that of the control ß-LG. Thus, the ratio of 1:4 was chosen to conjugate ß-LG with FOS, and the functional properties and conformational changes of ß-LG-FOS conjugates were investigated. The functional properties (solubility, emulsifying ability, and emulsion stability) of ß-LG were enhanced after conjugation with FOS. Furthermore, the molecular weight of ß-LG increased from 18.4 to 19.9 kDa after conjugation with FOS, as evaluated by sodium dodecyl sulfate-PAGE and mass spectrometry. Partial unfolding of ß-LG occurred after conjugation with FOS, as reflected by the quenching of fluorescence, the red-shift of fluorescence spectra, and the increase of ß-strands, which may contribute to the decrease in antigenicity and the improvement of functional properties.

Aggregation and conformational changes of bovine ß-lactoglobulin subjected to dynamic high-pressure microfluidization in relation to antigenicity.

Our previous research indicated that dynamic high-pressure microfluidization (DHPM) had a significant effect on the antigenicity of ß-lactoglobulin (ß-LG). In this study, aggregation and conformational changes subjected to DHPM (0.1-160 MPa) were investigated in relation to antigenicity. When DHPM pressure increased from 0.1 to 80 MPa, disaggregation of ß-LG samples and partial unfolding of the molecule were accompanied by an increase in ß-LG antigenicity, which was reflected in the decrease of particle size, increase of free sulfhydryl (SH) contents and ß-strands contents, and slight exposure of aromatic amino acid residues. At pressures above 80 MPa, the reaggregation of ß-LG may contribute to the decrease in antigenicity, which was reflected by an increase in particle size, the formation of aggregates, a decrease of in SH and ß-strands contents, and slight changes in aromatic amino acid residues. Aggregation and conformational changes of ß-LG under DHPM was related to its antigenicity.

Magnetic properties of Cu(m)O(n) clusters: a first principles study.

Experimental evidence shows that small Cu(2)O nanoparticles exhibit ferromagnetic or paramagnetic properties, allowing for the promising possibility to recycle the catalyst Cu(2)O easily in wastewater treatment. In this paper, theoretical calculation studying the magnetic property of copper/oxide clusters is reported. A series of Cu(m)O(n) ((m, n) = (4, 1); (4, 2); (4, 5); (16, 15); (28, 15); (44, 15); (28, 27)) clusters were investigated using generalized gradient approximation (GGA) and the Hubbard U (GGA+U) method within density functional theory (DFT). It is found that the electronic structures of bulk Cu(2)O calculated by the GGA and GGA+U are similar. The structures of Cu(m)O(n) ((m, n) = (4, 1); (4, 2); (4, 5)) are all planar. For the bulk-product Cu(m)O(n) ((m, n) = (16, 15); (28, 15); (44, 15); (28, 27)), O atoms prefer to be the outermost atoms. We classified two types of clusters on the basis of their O to Cu atomic ratios. One is O-rich clusters, i.e., Cu(4)O(5), Cu(16)O(15), and Cu(28)O(27). The other is O-poor clusters, i.e., Cu(4)O, Cu(4)O(2), Cu(28)O(15), and Cu(44)O(15). The calculation results show that the O-rich clusters have longer average Cu-Cu bonds and larger binding energy than those of the O-poor ones. More interestingly, the former are magnetic and give ferromagnetic ordering while the latter are nonmagnetic. The hydrogenation of O-terminated clusters can improve its stability but suppress its magnetism. The study may be extremely useful for the potential applications of Cu(2)O nanoparticles in the catalysis and semiconductor fields.

Ferroelectricity and ferromagnetism of La(0.5)Lu(0.5)Ni(0.5)Mn(0.5)O(3) thin films on Nb:SrTiO(3) substrates.

Epitaxial orthorhombic La(0.5)Lu(0.5)Ni(0.5)Mn(0.5)O(3) (LLNMO) thin films deposited on Nb:SrTiO(3) (NSTO) substrates are prepared by pulsed laser deposition and their ferroelectricity and magnetism are investigated using various techniques. It is revealed that the as-prepared thin films are ferromagnetic (FM) insulators. The FM transition occurring at ∼ 125 K is evidenced by the well defined hysteresis at low temperature, with a saturated magnetic moment as high as 1.8 µ(B)/f.u. at ∼ 5 K. A reversible ferroelectric polarization of ∼ 0.2 µC cm(-2) below ∼ 140 K is also observed. The magnetism can be understood by the FM ordering associated with a partially ordered major Ni(2 +)-Mn(4 +) plus minor Mn(3+)-Ni(3+) configuration, while the ferroelectricity is argued to originate from the A-site disordering of La(3+) and Lu(3+).

Competition between quantum fluctuations and antiferroelectric order in Ru-doped Sr(0.8)Ca(0.2)Ti(1-x)Ru(x)O(3).

The competition between quantum fluctuations and the antiferroelectric state in Sr(0.8)Ca(0.2)Ti(1-x)Ru(x)O(3) is investigated by measuring the low-temperature dielectric permittivity and by Raman spectroscopy. We demonstrate the significant impact of quantum fluctuations on the stability of the antiferroelectric polar order. It is revealed that the structural phase transitions can be modified by the quantum fluctuations, enhancing the stability of the high-symmetry phase and suppressing the antiferroelectric transitions. More importantly, a quantum antiferroelectric state, exhibiting similar behavior as the quantum ferroelectric state in terms of dielectric response, is identified. In addition, the effect of quantum fluctuations on the increasing permittivity at low temperature is also discussed.

A first-principles study of linear and nonlinear optical properties of 4-nitro-4'-methylbenzylidene aniline.

First-principles calculations of two second-order optical response functions as well as the dielectric function for 4-nitro-4(')-methylbenzylidene aniline are performed. Specifically, we evaluate the dielectric function and the second-harmonic generation (SHG) response coefficient over a wide frequency range. Electronic structure obtained from the full-potential projected augmented wave method is adopted in the calculation of optical properties. The calculated results of the refractive indices and the SHG are in good agreement with the experimental values. The linear and nonlinear optical spectra are analyzed and the origins of the peaks in the spectra are discussed in terms of the calculated electronic structure. It is found that the origin of the large nonlinear optical susceptibility is the charge transfer due to the strong "push-pull" effect. The study of the contributions of different transitions to the SHG coefficients shows that the virtual electron process is main. The contribution to the largest component chi(11) ((2)) of the virtual hole process is about 30% of the total static limit of the SHG coefficient. The prominent features in the spectrum of chi(11) ((2)) are successfully correlated with the features of the linear dielectric function epsilon(omega) in terms of single-photon and two-photon resonances.

Expressions of IGF-1 and TGF-beta 1 in the condylar cartilages of rapidly growing rats.

OBJECTIVE: This study was designed to investigate the expressions of IGF-I and TGF-beta 1 in condyles and to determine if the special modeling and remodeling of the condylar cartilages are regulated by growth factors. METHODS: Fifty 5-weeks-old male rats were assigned to five groups randomly, and one group was sacrificed every week. The condyles were harvested from rats whose ages ranged from 5- to 9-weeks-old and they were inspected by using S-P immunocytochemical techniques. RESULTS: IGF-I and TGF-beta 1 are expressed during condylar cartilage development in a temporally and spatially regulated fashion, and different growth factors have different expressing characteristics. The expressions of IGF-I are more intense in germinal and transitional layers, while TGF-beta 1 expression was high in the mature and degenerated layers. In germinal and transitional layers, IGF-I expression was high at the beginning of rapid growth, while TGF-beta 1 expression was low. At the end of the rapid growth, IGF-I expression was lower and TGF-beta 1 expression was still high. In the mature and degenerated layers, TGF-beta 1 expression was very high, while IGF-I expression was lower throughout rapid growth. CONCLUSIONS: The growth factors are expressed differentially, and each shows specific or overlapping localization patterns depending on the stage of developmental process, meaning that IGF-I and TGF-beta 1 may regulate condylar cartilage proliferation and differentiation in an interrelated system. This study suggests that growth factors can be produced locally by condylar cartilages and play an important role in the metabolism of condylar cartilages.

[Clinical application of the Begg light wire technique].

The authors analysed the typical malocclusion cases treated by Begg light wire technique and discussed the following questions: 1. Case selection: should pay great attention to the maxillofacial growth pattern, differentiate the type of deformities, dental or skeletal. 2. The overbite cases were corrected chiefly by incisor intrusion and molar extrusion. 3. The effect of intermaxillary elastics to anchorage teeth and movement teeth was evaluated. 4. Problems and solutions in all treatment stages, advantages and disadvantages of Begg technique were all discussed.