A theoretical study of Ar8+-acetylene collisions at 1.2 MeV: Ionization and dissociation dynamics.

We theoretically study Ar8+-induced dissociation of C2H2 molecule at 1.2 MeV using the time-dependent density-functional theory non-adiabatically coupled to nuclear dynamics. We find that molecular dissociation depends strongly on the ionization at the initial stage and the collision configuration. A detailed analysis shows a correspondence between the charge state of [C2H2]q+ and the final fragments. A remarkable impact parameter effect provides deep insights of bond breakup and electronic transport. We analyze two typical sequential dissociation channels reported in experiments by tracking structural and electronic dynamics in real time. Our results provide better understanding of experiments. Moreover, the comparison between various exchange-correlation functionals reveals that electrons' correlation and self-interaction do not significantly impact the initial ionization and fragment distribution in the present study.

[Non-carcinogenic health risk assessment of nickel in agricultural products and drinking water in an e-waste dismantling area of Qingyuan City, Guangdong Province].

Vegetables, rice, eggs and drinking water samples were collected from e-waste dismantling area of Qingyuan City, Guangdong Province. Nickel (Ni) was analyzed in each sample, and the non-carcinogenic health [the daily intake (DI) and hazard quotient (HQ)] of each sample was evaluated. In this e-waste dismantling area, the contents of Ni in rice and eggs were (0.46±0.24) and (0.16±0.13) µg/g, which were higher than those in the control area [the contents of Ni in rice and eggs were (0.17±0.03) and (0.02±0.02) µg/g, respectively] (both P values<0.05). The DI values of rice, vegetable, eggs, and drinking water were (3.61-5.86), (1.75-2.99), (0.11-0.24), and (0.08-0.12) µg·kg(-1)·day(-1), respectively. The HQ values were 0.180-0.290, 0.090-0.150, 0.005-0.010, 0.005-0.006, respectively. Although the HQ values of rice, vegetable, eggs, and drinking water were all lower than 1, which was an acceptable level. However, considering the possibility of combined exposure of heavy metals, the non-carcinogenic health risks of Ni in the e-waste dismantling area should still be concerned.

Effects of human parathyroid hormone on bone morphogenetic protein signal pathway following spinal fusion in diabetic rats.

Osteoporosis is a major complication in patients with diabetes mellitus. Thus, it is crucial to study the signal mechanisms responsible for enhancement of bone mass in diabetes. Administration of human parathyroid hormone (hPTH) has been reported to prevent osteoblast apoptosis and have anabolic effects on bone in animals and humans. In the present study, we examined the effects of hPTH on expression of bone morphogenetic protein type 2 (BMP-2) and its receptor BMPR2 in diabetic rats following spinal fusion. Our data show that hPTH amplified BMP-2 and BMPR2 in bone tissues of non-diabetic rats, but not in diabetic rats. Our data further demonstrate that hPTH plays a role in regulating BMP-2 and BMPR2 via mTOR-PI3K signal pathway. We suggest specific signaling pathways by which hPTH regulates BMP-2 via mTOR-PI3K mechanism in bone formation following spinal fusion. Notably, our data indicate under diabetic conditions this signal pathway is impaired, thereby likely affecting bone formation after spinal fusion. The subsequent induction of BMP-2 and BMPR2 are likely a part of the protective effects aimed at attenuating pathological bone damage as a result of diabetes.

Towards the analysis of attosecond dynamics in complex systems.

We study from a theoretical perspective the ionization of molecules and clusters induced by irradiation of a combined two-color laser field consisting of a train of attosecond XUV pulses in the presence of an IR field. We use time-dependent density-functional theory (TDDFT) in real time and real space as a theoretical tool. The calculated results are compared to experimental data when available. We also compare TDDFT with results obtained using a time-dependent Schrödinger equation (TDSE), which is well suited to simple systems while TDDFT allows dealing with more complex molecules and clusters. As a key observable, we study ionization versus delay time of the XUV pulses with respect to the IR background pulse. Experiments in simple atoms (He and Ar) show a regular modulation of this signal with half the IR period. This feature is recovered by TDDFT as well as by the TDSE (although total ionization differs by an order of magnitude). As more complex systems, we consider a C3 chain molecule and Na clusters. Here we encounter a different picture as the ionization signal develops a more involved pattern with several peaks per half IR period and as the TDSE produces a different pattern to TDDFT. Both effects could be related to the appearance of strong resonance modes in these more complex systems.

[Effects of saliva contamination on bond strength of resin-resin interfaces].

OBJECTIVE: To estimate the bond strength between different resin composite interfaces, and to evaluate the effect of saliva contamination and management with the contamination on the bond strength. METHODS: Two commercial resin composites containing different types of fillers (AP-X: barium-glass; P60: quartz) were tested in this study. The basic composite blocks were made of AP-X. After wet-ground flatted, the experimental groups were divided into three groups according to the surface treatment: (1)Direct bonding group: the bonding surface was rinsed with distilled water for 20 s, then dried with oil-free air for 20 s; (2)Saliva contamination group: the bonding surface was bathed in saliva for 30 min, then distilled water was rinsed for 20 s and dried with oil-free air for 20 s; (3)Saliva contamination and 75% ethanol wiping group: bonding surface bathed in saliva for 30 min, then wipe the surface with 75% ethanol, distilled water rinse for 20 s and dry with oil-free air for 20 s; The control group was made of the basic composite bulks of AP-X directly bonding with composite P60. Cut each resin block into 1 mm×1 mm×14 mm sticks, observing the micro-structures and detecting the micro-tensile strength of the resin composite interfaces. The bonding strength was measured using micro-tensile tester, then calculated and statistically analyzed by one-way ANOVA. RESULTS: Scanning electronic microscope observation revealed that the control group as well as the direct bonding subgroups, two different resin tags were in good contact with each other. The saliva contamination subgroups had lots of gaps or craters, indicating saliva might have been trapped in the composite buildup and wiping the surface with 75% ethanol had no effect. The micro-tensile bond strength of the control group was (84.07±1.57) MPa and significantly higher than all the other 3 experimental subgroups(P<0.001). In experimental groups, the micro-tensile strength of 3 subgroups was (76.08±2.42) MPa, (70.98±2.33) MPa and (71.08±2.33) MPa, respectively. The saliva contamination subgroup was significant lower than the direct bonding subgroup(P<0.001), but no statistical significance with the ethanol wiping subgroup(P=0.893). CONCLUSION: The bond strength of inner polymerization of resin-resin was greater, but decreased after resin composites interfacial bonding. Saliva contamination reduced the tensile bond strength between resin composites surface, wiping the surface with 75% ethanol had no effect.

STAT1 inhibitor alleviates spinal cord injury by decreasing apoptosis.

Spinal cord injury (SCI) is typically caused by trauma or disease, and it severely affects patients' motor function. The relationship between signal transducers and activators of transcription-1 (STAT1) and neuronal death after cerebral focal ischemia has been comprehensively studied, but its role in SCI remains largely unknown. This study investigated the protective effect of an STAT1 inhibitor on SCI. Thirty SD rats were SCI-induced and were then randomly divided into two groups (N = 15 each), either receiving STAT1 or the STAT1 inhibitor S1491 by intraperitoneal injection. The motor dysfunction of the rats was evaluated by behavioral scores, followed by the examination of SCI by hematoxylin and eosin staining. Apoptosis was also detected by Western blot and terminal deoxynucleotidyl transferase-mediated dUTP nick-end-labeling (TUNEL) assay. The motor functions of rats receiving STAT1 did not score as well as the STAT1 inhibitor group (P < 0.01). Further assays showed remarkable improvements in pathological damage to spinal code tissue in STAT1 inhibitor-treated rats, along with lower Bax and higher Bcl-2 expression. The STAT1 inhibitor also suppressed the occurrence of TUNEL-positive cells compared to the STAT1-treated group. In summary, we suggest that the STAT1 inhibitor alleviates SCI by decreasing apoptosis.

[Consensus of experts on the oral health management and medical risk prevention for the patients with chronic airway diseases (2022 edition)].

Today, there is greater awareness on the association between oral diseases and respiration diseases after the outbreak of COVID-19. However, confusion regarding the oral health management and medical risk prevention for patients with chronic airway diseases has been remained among dental clinicians. Therefore, the dental experts of the Fifth General Dentistry Special Committee, Chinese Stomatological Association, combined with the experts of respiratory and critical care medicine, undertook the formation of consensus on the oral health management of patients with chronic airway diseases in order to help dental clinicians to evaluate medical risks and make better treatment decision in clinical practice. In the present consensus report, the relationship of oral diseases and chronic airway diseases, the oral health management and the treatment recommendations of patients with chronic airway diseases are provided.

[Consensus of experts on the medical risk prevention for the patients with cardiovascular diseases during dental treatment (2022 edition)].

With the aging process of population in the society, the prevalence of cardiovascular diseases (CVD) in China is increasing continuously and the number of dental patients with CVD is increasing gradually too. Due to the lack of guidelines for dental patients with CVD in our country, how to implement standardized preoperative evaluation and perioperative risk prevention remains a problem to be solved for dentists at present. The present expert consensus was reached by combining the clinical experiences of the expert group of the Fifth General Dentistry Special Committee, Chinese Stomatological Association and respiratory and cardiology experts in diagnosis and treatment for CVD patients, and by systematically summarizing the relevant international guidelines and literature regarding the relationship between CVD and oral diseases and the diagnosis and treatment of dental patients with heart failure, hypertension and antithrombotic therapy. The consensus aims to provide, for the dental clinicians, the criteria on diagnosis and treatment of CVD in dental patients in China so as to reduce the risk and complications, and finally to improve the treatment levels of dental patients with CVD in China.

[c-myc gene and p53 protein expression in human primary liver carcinoma].

Photobiotin-labelled c-myc gene probe was used to study primary liver carcinoma (PHC) by in situ hybridization on the paraffin sections as well as immunohistochemistry staining for p53 protein expression in 42 cases from high liver cancer incidence regions. The results are as follows: c-myc gene and p53 protein expression were both located in the nuclei. The positive incidences of overexpression of both c-myc gene and p53 protein in PHC were 76% and 55% respectively. The distribution and strength of the overexpression of c-myc gene and p53 protein in PHC are related to the degree of cell differentiation and the overexpression in the liver tissue surrounding the carcinoma is lower than that detected in the PHC tissue.

[A study of temperature rising during the excimer laser keratectomy].

Here, we try to study the regularity of the temperature changing in radiated materials during excimer laser pho-torefractive keratectomy, and more attention should be paid to it during the excimer laser keratec[symbol: see text]tomy.