[Comparison of alignment and position of prosthesis between portable accelerometer-based navigation device and conventional instrumentation in total knee arthroplasty with valgus deformity].

Objective: To explore the differences of alignment and position of prosthesis between portable accelerometer-based navigation device (PAD) and conventional instrumentation (CI) in total knee arthroplasty (TKA) with valgus deformity. Methods: Patients with knee osteoarthritis and valgus deformity who underwent primary TKA in Peking University Third Hospital from January 2017 to December 2020 were enrolled in this retrospective study and were divided into PAD group and CI group according to the surgical instruments. Five male patients and 44 female patients were included with a mean age of (67.2±7.0) years. The differences in preoperative general data, preoperative and postoperative alignment between the two groups were studied. Results: A total of 49 patients (25 patients in the PAD group and 24 in the CI group) were enrolled in this study. There were no statistically significant differences in gender, age, height, weight, body mass index, surgical side, preoperative hip-knee-ankle (HKA) angle, preoperative HKA angle deviation, Keblish classification and Ranawat classification between the two groups (all P>0.05). There was no significant difference in the accuracy of postoperative HKA angle (2.0°±1.4° vs 3.0°±2.2°, P=0.082), coronal femoral component angle (CFCA) (1.5°±1.2° vs 2.1°±1.6°, P=0.144) and coronal tibial component angle (CTCA) (1.2°±0.8° vs 1.3°±1.0°, P=0.695) between the two groups; but the standard deviation of the above-mentioned three indices in PAD group were all smaller than those in CI group. The rate of outliers of postoperative HKA angle of the PAD group was smaller than that in the CI group (P<0.05), but there was no significant difference in the rate of outliers of CFCA and CTCA between the two groups (both P>0.05). Conclusion: TKA assisted by PAD can provide good alignment and prosthesis position in patients with valgus deformity, and it is superior to TKA with CI in terms of precision and rate of outliers of postoperative overall alignment of lower extremity.

Linoleic acid and α-linolenic acid inhibit conjugative transfer of an IncX4 plasmid carrying mcr-1.

AIMS: The aim of this study was to determine the effects of unsaturated fatty acids on clinical plasmids. METHODS AND RESULTS: Two unsaturated fatty acids, linoleic acid (LA) and α-linolenic acid (ALA) at final concentration 0, 0·03, 0·3 and 3 mmol l-1 , respectively, were used to assess the effects on conjugative transfer of a mcr-1-harbouring plasmid pCSZ4 (IncX4) in conjugation experiment. The inhibitory mechanisms were analysed by molecular docking and the gene expression of virB11 was quantitated by qRT-PCR. Target plasmid diversity was carried out by TrwD/VirB11 homology protein sequence prediction analysis. Our results showed that LA and ALA inhibit plasmid pCSZ4 transfer by binding to the amino acid residues (Phe124 and Thr125) of VirB11 with dose-dependent effects. The expression levels of virB11 gene were also significantly inhibited by LA and ALA treatment. Protein homology analysis revealed a wide distribution of TrwD/VirB11-like genes among over 37 classes of plasmids originated from both Gram-negative and Gram-positive bacteria. CONCLUSIONS: This study demonstrates representing a diversity of plasmids that may be potentially inhibited by unsaturated fatty acids. SIGNIFICANCE AND IMPACT OF THE STUDY: Our work reported here provides additional support for application of curbing the spread of multiple plasmids by unsaturated fatty acids.

[Comparison of alignment between computer assisted surgery and personal specific instrumentation in total knee arthroplasty].

Objective: To explore the differences of alignment and operative time between computer assisted surgery (CAS) and personal specific instrumentation (PSI) in total knee arthroplasty (TKA). Methods: Patients with knee osteoarthritis who underwent unilateral primary TKA in Peking University Third Hospital from June 2019 to April 2021 were enrolled in this prospective study and were randomly divided into CAS group and PSI group with random number table. The differences in preoperative general data, operative time, preoperative and postoperative alignment between the two groups were studied. Results: A total of 80 patients were enrolled in this study, including 40 patients in the CAS group with an average age of (68±6) years (male/female, 6/34 cases) and 40 patients in the PSI group with an average age of (69±6) years (male/female, 5/35 cases). There was no significant differences in gender, age, height, weight, body mass index, surgical side, preoperative hip-knee-ankle (HKA) angle, and preoperative HKA angle deviation between the two groups (all P>0.05). The accuracy of sagittal femoral component angle (sFCA) (1.7°±1.2° vs 2.5°±1.4°, P<0.05) and sagittal tibial component angle (sTCA) (1.2°±0.9° vs 2.3°±1.8°, P<0.01) of the CAS group were both smaller than those in the PSI group, but there was no significant difference in the accuracy of postoperative HKA angle, mechanical lateral distal femoral angle (mLDFA) and mechanical medial proximal tibia angle (mMPTA) between the two groups (all P>0.05). The precision of postoperative HKA angle and sTCA of the CAS group were both smaller than those in the PSI group (2.0°±1.0° vs 2.6°±1.7°, 1.2°±0.9° vs 2.3°±1.8°, both P<0.01), but there was no significant differences in the precision of mLDFA, mMPTA and sFCA between the two groups (all P>0.05). The rate of outliers of postoperative HKA angle (10.0% vs 27.5%, P<0.05), sFCA(5.0% vs 20.0%, P<0.05) and sTCA (2.5% vs 22.5%, P<0.01) of the CAS group were all smaller than those in the PSI group, but there was no significant difference in the rate of outliers of mLDFA and mMPTA between the two groups (both P>0.05). CAS group had significantly longer surgical time than the PSI group ((81±12) min vs (52±8) min, P<0.01). Conclusions: CAS is better than PSI in overall coronal alignment and sagittal position of the prosthesis after TKA. However, CAS requires a longer operation time.

[Identification of characteristic methylation sites in gastric cancer using genomics-based machine learning].

Objective: To construct a prediction model of gastric cancer related methylation using machine learning algorithms based on genomic data. Methods: The gene mutation data, gene expression data and methylation chip data of gastric cancer were downloaded from The Caner Genome Atlas database, feature selection was conducted, and support vector machine (radial basis function), random forest and error back propagation (BP) neural network models were constructed; the model was verified in the new data set. Results: Among the three machine learning models, BP neural network had the highest test efficiency (F1 score=0.89,Kappa=0.66, area under curve=0.93). Conclusion: Machine learning algorithms, particularly BP neural network, can be used to take advantages of the genomic data for discovering molecular markers, and to help identify characteristic methylation sites of gastric cancer.

Primary vs myocutaneous flap closure of perineal defects following abdominoperineal resection for colorectal disease: a systematic review and meta-analysis.

AIM: Perineal wound complications after abdominoperineal resection (APR) have become a major clinical challenge. Myocutaneous flap closure has been proposed in place of primary closure to improve wound healing. We conducted this comprehensive meta-analysis to evaluate the current scientific evidence of primary closure vs myocutaneous flap closure of perineal defects following APR for colorectal disease. METHODS: We systematically searched the MEDLINE, Embase, PubMed, Web of Science and Cochrane Library databases to identify all relevant studies. After data extraction from the included studies, meta-analysis was performed to compare perioperative outcomes of primary closure and myocutaneous flap closure. RESULTS: Eighteen studies with a total of 17 913 patients (16 346 primary closure vs 1567 myocutaneous flap closure) were included. We found that primary closure was significantly associated with higher total perineal wound complications (P = 0.007), major perineal wound complications (P < 0.001) and perineal wound infection (P = 0.001). On the other hand, myocutaneous flap closure takes more operation time (P < 0.001) and increases the risk of perineal wound dehiscence (P = 0.01), deep surgical site infection (P < 0.001), enterocutaneous fistulas (P = 0.03) and return to the operating room (P = 0.0005). There were no significant differences between the two groups for other outcomes. CONCLUSIONS: This is the first systematic review with meta-analysis comparing primary closure with myocutaneous flap closure of perineal defects after APR for colorectal disease. Although taking more operation time and an increased risk of specific complications, the pooled results have validated the use of myocutaneous flaps for reducing total/major perineal wound complications. More investigations are needed to draw definitive conclusions on this dilemma.

[Discussion on optimal duration of pegylated interferon α combined with ribavirin for chronic hepatitis C in HIV-infected patients].

Objective: To investigate the optimal duration of pegylated-alpha interferon (Peg-INFα) combined with ribavirin (RBV) in treating chronic hepatitis C infection in human immunodeficiency virus (HIV)-infected patients. Methods: A multicenter prospective study was conducted. The study subjects were divided into two groups; HIV/HCV co-infections (Group A, n = 158) and control with HCV-monoinfections (Group B, n = 60). All recruited patients received standard Peg-INFα plus RBV therapy. Group A was divided into 3 subgroups according to CD4(+) cell counts: A1 subgroup, 79 cases, CD4(+) counts > 350 cells /µl, who received anti-HCV before combination antiretroviral therapy(cART); A2 subgroup, 45 cases, CD4(+) counts between 200 and 350 cells/µl, who did not start anti-HCV until they could tolerate cART well; A3 subgroup, 34 cases, CD4(+) counts < 200 cells /µl, cART was administered first, and anti-HCV therapy was started when CD4(+) counts > 200 cells/µl. The anti-HCV efficacy of two groups and 3 subgroups were compared. Statistical analysis for normal distribution and homogeneity of variance data was calculated by t-test and the counting data was analyzed by χ (2) test. The Mann-Whitney U test was used for non-normal data. A one-way analysis of variance (ANOVA) was used for the comparison of multiple groups, followed by SNK method. Multiple independent samples were used for non-parametric tests. Results: There was no significant difference in age and baseline HCV RNA levels between groups and subgroups (P > 0.05). By an intent-to-treat (ITT) analysis, in Group A, the ratio of complete early virological response (cEVR) rate was 75.3% (119/158), the ratio of end of treatment virological response (eTVR) rate was 68.4% (108/158), and the ratio of sustained virological response (SVR) rate was 48.7% (77/158); in Group B, the ratio of cEVR rate was 93.3% (56/60), the ratio of eTVR rate was 90.0% (54/60), and the ratio of SVR rate was 71.7% (43/60); The therapeutic index of Group A were lower than those of Group B (P≤0.05). By per-protocol (PP) analysis, the ratio of cEVR rate in Group A [75.2% (88/112)] was still lower than that in Group B [93.3% (56/60)], but no significant differences were found in the ratio of eTVR rate and SVR rate between 2 groups (P > 0.05). Comparing the efficacy of subgroups (A1, A2 and A3) by ITT analysis, the ratios of cEVR rate were respectively 78.5% (62/79), 75.6% (34/45) and 67.6% (23/34); the ratios of eTVR rate were respectively 68.4%(54/79), 80.0%(36/45)and 52.9%(18/34); and the ratios of SVR rate were respectively 41.8%(33/79), 64.4%(29/45)and 44.1%(15/34). The ratio of eTVR in subgroup A2 was obviously higher than that in subgroup A3 and the ratio of SVR in subgroup A2 was statistically higher than that of subgroup A1(P≤0.05). However, by PP analysis, no significant differences of the therapeutic indexes were found among the respective subgroups (P > 0.05). Conclusion: HIV-HCV co-infected patients would have better anti-HCV efficacy with Peg-INFα-2a plus RBV than HCV- monoinfected patients. The best time for initiating anti-HCV therapy in HIV-HCV co-infected patients is when CD4(+) counts 200 cells/ µl.

Effects of lipopeptide carboxymethyl chitosan nanoparticles on Staphylococcus aureus biofilm.

This study aims to evaluate the effect of lipopeptide carboxymethyl chitosan nanoparticles on Staphylococcus aureus biofilm as part of the development of a new anti-biofilm material. The study had three stages. Firstly, we assessed the Staphylococcus aureus capability to form biofilm and enumerated the number of attached bacteria and free bacteria; secondly, we determined the inhibitory effect of different concentrations of Bacillus natto antimicrobial lipopeptid- carboxymethyl chitosan (BNAP-CMCS) nanoparticles added at different times on biofilm formation capability and the numbers of free bacteria and attached bacteria. Lastly, we tested the scavenging effect of BNAP-CMCS nanoparticles on biofilm formation and number of attached bacteria. The results showed that the amount of attached bacteria quickly increased over time and reached the maximum after 24 h of culture. The BNAP-CMCS nanoparticles had the greatest effect on biofilm inhibition at the concentration of 1 MIC, after 8 h of culture, and the effect was dose-dependent. The BNAP-CMCS nanoparticles had decreased also the numbers of free and attached bacteria in a dose-dependent fashion, after 8 hours of culture. The scavenging effect of BNAP-CMCS nanoparticles on free and attached bacteria was maximum at 6 MIC. In conclusion, lipopeptide carboxymethyl chitosan nanoparticles had a good inhibition and scavenging effect on the formation of Staphylococcus aureus biofilm and the growth of surface-attached bacteria.

[Experimental study scavenging effect of paraquat by hemoperfusion].

Objective: To determine the scavenging effect and the change of metabolism of paraquat (PQ) using hemoperfusion (HP) once and twice within 12 hours after intoxication and explore the better scheme of HP. Methods: 18 beagles were randomly divided into 3 groups. Single HP group, Double HP group and Control group. Peripheral veins blood was collected at different times within 48 hours after exposure in each group. Toxin concentration was measured, analyzed and compared among 3 groups. Results: 6 hours after exposure, Single HP group and Double HP group has finished the first HP treatment, and the concentration of PQ was lower than that of the control group, the difference was statistically significant (P<0.05) . 10 hours after exposure, there was no statistical difference of toxin concentration among 3 groups (P>0.05) . 12 hours after exposure, Double HP group has finished the second HP treatment, the concentration of PQ was significantly lower than that of Single HP group and Control group (P<0.05) . 24 hours and 48 hours after exposure, there was no statistical difference of toxin concentration among 3 groups (P>0.05) . Statistical difference were not observed in toxicokinetical parameters among 3 groups (P>0.05) . Conclusion: HP treatment once and twice within 12 hours after intoxication could effectively reduce the toxin concentration in the peripheral veins blood after HP for about 4 hours, then the toxin concentration would return to the same level as Control group quickly. It was suggested that at the beginning of poisoning, HP treatment once or twice could not significantly change the metabolism of paraquat.

Effect of androgen deprivation on the expression of aquaporins in rat prostate and seminal vesicles.

The aim of this study was to investigate the level of secretions of prostate and seminal vesicles and its association with the expression of AQP0, 1, 4, 5, 6 and 8 in castrated rats. Eight-week-old male Sprague-Dawley (SD) rats (n = 18) were randomly divided into control group, castrated rats group and castrated followed testosterone replacement group. Four weeks after surgery, the secretions and expression of AQP0, 1, 4, 5, 6 and 8 of prostate and seminal vesicles were determined. Serum testosterone was significantly lower in castrated groups than in control and testosterone replacement groups (P < 0.05). The level of prostate and seminal vesicle secretions and the expressions of AQP0, 1, 4, 5, 6 and 8 in prostate and seminal vesicles were significantly lower in castrated group than in control and castrated followed testosterone replacement groups (P < 0.05). The decreased prostatic and seminal vesicle secretions in castrated rats may be related to the decrease in AQP0, 1, 4, 5, 6 and 8 in prostatic tissue and seminal vesicles.

Effect of procyanidine on VEGFR-2 expression and transduction pathway in rat endothelial progenitor cells under high glucose conditions.

The protective effect of procyanidine and its oligomers against high glucose-mediated oxidative stress injury in endothelial progenitor cells (EPCs), and effect of procyanidin on vascular endothelial growth factor receptor-2 (VEGFR-2) expression and downstream signal pathway were analyzed in vitro. Rat bone marrow mononuclear cells were isolated, cultured under normal and high glucose (HG) conditions, and the changes in cell morphology observed. The EPCs were identified, and the oxidative stress products produced by EPCs (under normal and HG conditions) were quantified. Subsequently, an appropriate number of EPCs were cultured with and without procyanidin (OPC), and the MDA concentration and relative expression of VEGFR-2, AKT, IκB-α, and nuclear factor (NF)-κB were detected 1, 3, 5, and 7 days post-culture. We observed minor (round, translucent, gradually adhering) and significant (fusiform morphology/pebble distribution) cell morphological changes 3 and 7 days post-culture, respectively. Apoptosis and oxidative stress product release in EPCs cultured with HG increased significantly compared to the control group (P < 0.05). The oxidative stress product generation and relative expression of VEGFR-2, AKT, IkB-α, and NF-κB were not significantly affected by OPC addition in normal glucose conditions (P > 0.05); alternately, products generated as a result of oxidative stress were significantly reduced, the relative expression of VEGFR-2, AKT, and NF-κB protein was upregulated, and that of IκB-α was downregulated (P < 0.05) in HG + OPC EPCs. Therefore, procyanidin may promote cell proliferation by alleviating oxidative damage to EPCs under HG conditions, and upregulating VEGFR-2 expression and its downstream signal pathway.

Role of miR-149C>T polymorphisms on the risk of hepatocellular carcinoma in a Chinese population.

MicroRNAs (miRNAs) are thought to play a role in cancer development. We conducted a case-control study to investigate the association between polymorphisms in miR-149C>T and hepatocellular carcinoma (HCC) risk. Duplex polymerase chain reaction with the confronting 2-pair primers were taken to genotype miR-149C>T. The association between genotype frequencies of miR-149C>T and risk of HCC was estimated as odds ratios (ORs) and 95% confidence intervals (95%CIs) using conditional regression analysis. Logistical regression analysis showed that the miR-149 CC genotype and C allele were associated with risk of HCC, with adjusted ORs (95%CI) of 2.07 (1.32-3.26) and 1.42 (1.06-2.12), respectively. Using the TT+TC genotype as a reference, individuals carrying the CC genotype were associated with non-significant increased risk of HCC, adjusted OR (95%CI) of 1.37 (0.91-2.07). Subgroup analysis showed that HBV-infected subjects carrying the miR-149 TC+CC genotype (OR=5.85, 95%CI=2.49-13.77) had an increased risk of HCC. In summary, our study found that miRNA-149C>T polymorphism is associated with risk of HCC, especially in HBV-infected patients.

Effect of IL-18 gene promoter polymorphisms on prostate cancer occurrence and prognosis in Han Chinese population.

Interleukin-18 (IL-18) has been implicated in a wide variety of cellular functions that affect the biological response to tumors. However, there is insufficient evidence to prove that IL-18 gene variants are associated with risk of prostate cancer. We examined a possible association between two promoter polymorphisms, -137G/C (rs187238) and -607C/A (rs1946518), in the IL-18 gene and prostate cancer occurrence and prognosis in Han Chinese. We used a high-resolution melting method to genotype these two polymorphisms in 375 Chinese Han patients with prostate cancer and in 400 age-matched healthy controls. A hundred and eighty-one prostate cancer patients who had been receiving androgen deprivation therapy, including operational and medical castration, were enrolled to follow-up in this study. Carriers of the GG genotype of the -137G/ C polymorphism had a 2.165-times higher risk of prostate cancer progression than carriers of GC [95% confidence interval (CI) = 1.270-3.687]. Patients with the GG genotype at clinical stages III and IV also had significantly lower rates of progression-free survival (relative risk = 2.174, 95%CI = 1.211-3.906). However, we found no significant association of genotype or allele distributions of these two polymorphisms with occurrence of prostate cancer. We conclude that there is evidence that the IL-18 gene promoter polymorphism -137G/ C influences the prognosis of prostate cancer patients in androgen deprivation therapy, although neither of the two SNPs contributes to prostate cancer development.

Surgical treatment of tethered cord syndrome showed promising outcome in young children with short duration.

OBJECTIVE: Aside from the severity, surgical interventions for the treatment of neurological dysfunctions remain controversial. This study aimed to find factors predicting the benefits of tethered cord syndrome (TCS) surgery. PATIENTS AND METHODS: 80 children with TCS were included and followed up for pre- and post-operative factors along with neurophysiological analysis. Outcomes were assessed by univariate and multivariate analysis. RESULTS: Surgical treatment not only improved preoperative signs and symptoms in 79% of TCS patients but it showed to be an efficient procedure for the occurrence of future neurological defects. Univariate analysis also revealed that surgical intervention in TCS children (age <1 year) can modulate filar lipoma location and cutaneous abnormalities three months after surgery. Neurophysiological assessment revealed only 5.0% of surgical complications in TCS patients. Two patients had cerebrospinal fluid leakage, and two cases of CNS infection were detected. CONCLUSIONS: Surgical intervention is highly recommended for the prevention of neurological deficits in children with TCS. Electrophysiological monitoring revealed rare complications following the surgery.

Clinical characteristics and prognostic factors of surgical treatment in children with brainstem tumor.

OBJECTIVE: Brainstem tumors present a significant challenge in surgical treatment, and the prognostic factors in children are lacking. This study aimed to investigate clinical characteristics and prognostic factors of surgical treatment in children with brainstem tumors. PATIENTS AND METHODS: 50 children with brainstem tumors who underwent surgical treatment, including frameless- or frame-based stereotactic biopsy and resection, were included and followed up for clinical and biological analysis. Factors of outcomes were assessed by univariate and multivariate analysis. RESULTS: 27 cases (54.0%) underwent resection in all children with brainstem tumors. The rate of resection reached as high as 81.8% in children with non-diffuse intrinsic pontine glioma (DIPG), while in children with DIPG, biopsy was performed in the majority, and resection was obtained in the minority with focal necrosis. A rare complication was found following the surgery. Multivariate analysis considered World Health Organization (WHO) grade 3-4, with hazard ratio (HR)=4.48, 95% confidence interval (CI) of 2.84-8.69, p=0.001, H3K27M mutation (HR=2.50, 95% CI 1.73-5.69, p=0.015), and hydrocephalus (HR=2.17, 95% CI 1.08-5.32, p=0.014) as independent adverse prognostic factors. For Kaplan-Meier analysis, children with WHO grade 3-4, Ki-67 LI ≥ 20%, TP53 mutation, H3K27M mutation, DIPG, and hydrocephalus had significantly decreased overall survival (OS). CONCLUSIONS: A high rate of resection has been obtained in non-DIPG, and surgical intervention is remarkably safe and efficient for children with brainstem tumors. WHO grade 3-4, H3K27M mutation, and hydrocephalus indicate poor prognosis in children with brainstem tumors.

Investigations of clinical characteristics and inflammatory markers of febrile seizures induced by coronavirus infection.

The study of children who experienced with febrile seizures(FS) as a result of COVID-19 infection to gain insight into the clinical characteristics and prognosis of neurological damage, with the aim of improving prevention, diagnosis, and the treatment of neurological complications. This study investigated the clinical features of 53 children with FS who were admitted to Sanya Women and Children's Hospital from December 1, 2022, to January 31, 2023. The results indicated that the duration of convulsion in the case and control group was 7.90±8.91 and 2.67±1.23 (minutes) respectively. The analysis reveals that convulsions occurred within 24 hours in 39 cases (95.12%) of the case group, and in 8 cases (66.7%) of the control group. The difference was statistically significant (P<0.05). Additionally, the case group presented lower counts of WBC and NEU compared to the control group (p<0.05). The findings indicate that convulsions manifest at earlier stages of COVID-19 in children and the last longer than in the control group. It is therefore crucial for healthcare workers to remain attentive to patients with COVID-19 who report fever within 24 hours, and act promptly to implement preventive measures, particularly in cases of prolonged fever. It is essential to integrate the clinical manifestation, particularly convulsions, and the continuous numerical changes of inflammatory factors to assess COVID-19 linked with febrile seizures. In addition, larger-scale multi-center and systematic research are necessary to aid clinicians in monitoring neuropathological signals and biological targets, enabling more equitable diagnosis and treatment plans.

Spin-textures of medium-body boson systems with trapped spin-f cold atoms.

The spin-textures of bound medium-body systems with spin-[Formula: see text] atoms ([Formula: see text]) have been studied. The Hamiltonian is assumed to be dominated by the two-body interaction favoring parallel spins. The system with particle number [Formula: see text] and [Formula: see text] is first chosen, and the Hamiltonian is exactly diagonalized by using Fock-states as basis-states, thereby all the eigenenergies and eigenstates are obtained and a detailed analysis is made. Then the cases with [Formula: see text] and [Formula: see text] are further studied. Since the total spin S is conserved, the eigenstates having the same S form an S-group. Let the lowest (highest) energy state of an S-group be called a bottom-state (top-state). We found that all the bottom-states are bipartite product states with constituent states describing fully polarized subsystems containing [Formula: see text] and [Formula: see text] ([Formula: see text]) particles, respectively. For two bottom-states different in [Formula: see text], the one with a larger [Formula: see text] is higher. For two having the same [Formula: see text], the one with a smaller S is higher. Whereas all the top-states are found to be essentially a product state of the pairs, in each pair the two spins are coupled to [Formula: see text] if the strength of the [Formula: see text]-channel is more repulsive than the others. For the states belonging to an S-group, the higher one would contain more pieces. As the energy goes up, larger pieces (those containing more than two particles) will disappear.

A stable spin-structure found in a 3-body system with spin-3 cold atoms and its role in N-body condensates.

We have found a stable spin-structure of N [Formula: see text] 3 system in which three spin-3 atoms are trapped and coupled to total spin S [Formula: see text] 3. We have proved that a pair of this structure is nearly an exact solution for N [Formula: see text] 6 systems in a very broad district in the parameter-space. Comparing with the well-known singlet pairs, this pair is a more promising candidate to serve as a building block for large N systems with spin-3 atoms. This is because the spin-structure of the latter can be modified depending on the interactions to reduce the energy while the singlet pairs can not. In fact, we have proved that, for a specific set of strengths (a point in the parameter-space) the product state based on this pair is an exact solution of the N-body Hamiltonian. Thus, in the neighborhood of this point, the product state will appear as an approximate solution. However, how broad this neighborhood would be remains to be clarified.

Spin-structures of the Bose-Einstein condensates with three kinds of spin-1 atoms.

We have performed a quantum mechanic calculation (including solving the coupled Gross-Pitaevskii equations to obtain the spatial wave functions, and diagonalizing the spin-dependent Hamiltonian in the spin-space to obtain the total spin state) together with an analytical analysis based on a classical model. Then, according to the relative orientations of the spins SA, SB and SC of the three species, the spin-structures of the ground state can be classified into two types. In Type-I the three spins are either parallel or anti-parallel to each other, while in Type-II they point to different directions but remain to be coplanar. Moreover, according to the magnitudes of SA, SB and SC, the spin-structures can be further classified into four kinds, namely, p + p + p (all atoms of each species are in singlet-pairs), one species in f (fully polarized) and two species in q (a mixture of polarized atoms and singlet-pairs), two in f and one in q, and f + f + f. Other combinations are not allowed. The scopes of the parameters that supports a specific spin-structure have been specified. A number of spin-structure-transitions have been found. For Type-I, the critical values at which a transition takes place are given by simple analytical formulae, therefore these values can be predict.

[Prevalence of biomass fuel exposure in women aged 40 years and older in China, 2014].

Objective: To understand the prevalence of biomass fuel exposure in women aged ≥40 years in China during 2014-2015, and provide evidence for the prevention and control of bio-fuel exposure. Methods: All participants were selected from a national representative cross-sectional survey during 2014-2015 in the mainland of China. A multi-stage stratified cluster sampling strategy was used. A total of 37 795 women aged ≥40 years received a face-to-face questionnaire survey at 125 surveillance points in 31 provinces. The level of biomass fuel exposure was analyzed after complex sample weighting to represent the overall Chinese women aged ≥40 years. Results: A total of 37 777 women were included in the analysis. With complex weighting, the rate of biomass fuel exposure in Chinese women aged ≥40 years was 35.8% (95%CI: 29.6%-42.1%), the exposure rate was higher in rural women than in urban women (P<0.001). The biomass fuel exposure rate was highest in northeastern and lowest in northern areas of China (χ(2)=17.03, P=0.009). The estimated biomass fuel exposure rate decreased with the increase of educational level (P<0.001). Conclusion: The prevalence of biomass fuel exposure is high in women aged ≥40 years in China, especially in those in rural areas. The exposure level differs with age and area. Appropriate measures should be taken to reduce the level of biomass fuel exposure in Chinese women.

Singularity in the matrix of the coupled Gross-Pitaevskii equations and the related state-transitions in three-species condensates.

An approach is proposed to solve the coupled Gross-Pitaevskii equations (CGP) of the 3-species BEC in an analytical way under the Thomas-Fermi approximation (TFA). It was found that, when the strength of a kind of interaction increases and crosses over a critical value, a specific type of state-transition will occur and will cause a jump in the total energy. Due to the jump, the energy of the lowest symmetric state becomes considerably higher. This leaves a particular opportunity for the lowest asymmetric state to replace the symmetric states as the ground state. It was further found that the critical values are related to the singularity of either the matrix or a sub-matrix of the CGP. These critical values are not arising from the TFA but inherent in the CGP, and they can be analytically expressed. Furthermore, a model (in which two kinds of atoms separated from each other asymmetrically) has been proposed for the evaluation of the energy of the lowest asymmetric state. With this model the emergence of the asymmetric ground state is numerically confirmed under the TFA. The theoretical formalism of this paper is quite general and can be generalized for BEC with more than three species.