[Clinical research on posterior single-implant occlusal contact time and force changes].

Objective: To investigate the changes of occlusal delay time, percentage of occlusal force and patients' subjective satisfaction of masticatory function for single implant crown in one year after the application of space reserved occlusion design. To provide data support and suggestions for clinical occlusion design. Methods: Patients who had received single posterior dental implant restoration in Department of Prosthodontics, Capital Medical University School of Stomatology from January 2019 to December 2019 were selected. At 0.5, 3, 6 and 12 months after restoration, the T-scan Ⅲ occlusal analyzer was used to detect and record the initial occlusal contact time of the natural tooth and implanted single crown, the occlusal force percentage of single implant prosthesis and corresponding tooth on the contralateral side (control teeth) on the contralateral side (control teeth) were also recorded. Subjective satisfaction with the masticatory function of the implants was recorded using visual analogue scale (VAS). The changes of occlusal delay time (the difference of the initial occlusal time between implant restoration and the natural teeth), percentage of occlusal force and patients' subjective feeling with time were analyzed. All data were analyzed by repeated measurement analysis of variance, bilatteral P<0.01 was considered statistically significant. Results: A total of 48 patients aged (36.8±8.4) years (23 males, 25 females, aged 23-50 years) were recruited. The occlusal delay time at 0.5 months was 0.15 (0.08, 0.20) s, at 3 months was 0.11 (0.06, 0.16) s, at 6 months was 0.07 (0.03, 0.13) s and at 12 months was 0.06 (0.03, 0.10) s. The occlusal delay time was shortened at every two time points, and the occlusal force percentage of the implant crown increased significantly. The percentage of occlusal force of implant prosthesis at 0.5 months was (7.7±4.8)%, at 3 months was (10.6±5.9)%, at 6 months was (12.3±6.2)% and at 12 months was (13.2±6.7)%. The most significant change was during the period of 0.5-3 months. At 0.5 months, the occlusal force of implant prosthesis was significantly lower than that of control teeth (14.3±6.5)% (P<0.01). The VAS score at 0.5 months was (7.06±1.64) and was (8.71±0.74) at 12 months. The score was increased and the difference was statistically significant from 3 month to 12 month (P<0.01). Conclusions: The change of occlusal force percentage of single posterior dental implant is most obvious within 3 months after restoration. The occlusal condition should be reexamined and adjust occlusal after 3 months of implant restoration as appropriate.

Screening and characterization of aptamers for recombinant human programmed death-1 and recombinant extracellular domain of human programmed death ligand-1.

OBJECTIVE: Programmed death ligand-1 (PD-L1) is expressed on tumor cells and macrophages. The detection of PD-L1 expression in cancer and the treatment by targeting the PD-L1/programmed death-1 (PD-1) are of great clinical significance. This work aims to screen the aptamers with high affinity and specificity for recombinant human PD-1 (rhPD-1)/recombinant human PD-L1 extracellular domain (rhPD-L1). MATERIALS AND METHODS: In this study, we have expressed, purified, prepared, and identified rhPD-1 and rhPD-L1. The rhPD-L1/rhPD-1 aptamers with high affinity and specificity were obtained by systematic evolution of ligands by exponential enrichment technique. Ten aptamers sequences to rhPD-L1 and 10 aptamers sequences to rhPD-1 were obtained by cloning and sequencing. The affinity and specificity of candidate aptamers were analyzed by gold nanoparticles-based colorimetric assay, dot blot assay, and electrophoretic mobility shift assay. RESULTS: The aptamers named A6 were picked out as the optimal aptamers that recognize PD-1, specifically with the Kd value of 47.84 ± 24.78 nM. The aptamers named B10 were picked out as the optimal aptamers that recognize PD-L1, specifically with the Kd value of 59.72 ± 15.87 nM. CONCLUSIONS: The study lays a foundation for the development of detection methods and therapeutic drugs targeting PD-L1/PD-1.

Diagnostic Accuracy of Arterial Spin-Labeling MR Imaging in Detecting the Epileptogenic Zone: Systematic Review and Meta-analysis.

BACKGROUND: A noninvasive, safe, and economic imaging technique is required to identify epileptogenic lesions in the brain. PURPOSE: Our aim was to perform a meta-analysis evaluating the accuracy of arterial spin-labeling in localizing the epileptic focus in the brain and the changes in the blood perfusion in these regions. DATA SOURCES: Our sources were the PubMed and EMBASE data bases. STUDY SELECTION: English language studies that assessed the diagnostic accuracy of arterial spin-labeling for detecting the epileptogenic zone up to July 2019 were included. DATA ANALYSIS: The symptomatogenic foci of seizures in the brain were determined and used as the references. The relevant studies were evaluated using the Quality Assessment of Diagnostic Accuracy Studies-2 tool. The outcomes were evaluated using the pooled sensitivity, pooled specificity, pooled accuracy, diagnostic odds ratio, area under the summary receiver operating characteristic curve, and likelihood ratio. DATA SYNTHESIS: Six studies that included 174 patients qualified for this meta-analysis. The pooled sensitivity, pooled specificity, and area under the summary receiver operating characteristic curve were 0.74 (95% CI, 0.65-0.82), 0.35 (95% CI, 0.03-0.90), and 0.73 (95% CI, 0.69-0.76), respectively. The accuracy of arterial spin-labeling for localizing the epileptic focus was 0.88 (accuracy in arterial spin-labeling/all perfusion changes in arterial spin-labeling) in cases of a positive arterial spin-labeling result. The epileptogenic zone exhibited hyperperfusion or hypoperfusion. LIMITATIONS: Only a few studies were enrolled due to the strict inclusion criteria. CONCLUSIONS: Arterial spin-labeling can be used for assessing, monitoring, and reviewing, postoperatively, patients with epilepsy. Blood perfusion changes in the brain may be closely related to the seizure time and pattern.

Extracorporeal shock wave therapy (ESWT) may be helpful in the osseointegration of dental implants: A hypothesis.

In recent decades, with the rapid development of dental implant technology, dental implants have been widely used in clinical practice. Various complications, including a lack of osseointegration, may occur after dental implantation. However, the occurrence of osteointegration failure after dental implantation is often complicated and unpredictable, and existing treatment methods cannot reverse osteointegration failure to achieve the optimum condition. A noninvasive, easy-to-operate, low-cost, fast-acting mechanotherapy is expected to solve this problem. Extracorporeal shock wave therapy (ESWT) is widely used to treat delayed healing, bone nonunion fractures, femoral head necrosis and other orthopedic diseases and plays a significant role in promoting bone regeneration. Studies have shown that ESWT can promote bone formation and osseointegration of titanium devices in vivo. In previous experiments, ESWT was found to regulate the activity of inflammatory cells, osteoblasts and mesenchymal stem cells. Studies have also mentioned the role of ESWT in promoting angiogenesis and bactericidal activity. Therefore, our hypothesis is that extracorporeal shock wave therapy can facilitate the realization of osteointegration by regulating the immune response, inducing regeneration of the jaw and alveolar bone, and promoting angiogenesis and bactericidal efficacy.

Intrinsic Mechanism for Anisotropic Magnetoresistance and Experimental Confirmation in Co_{x}Fe_{1-x} Single-Crystal Films.

Using first-principles transport calculations, we predict that the anisotropic magnetoresistance (AMR) of single-crystal Co_{x}Fe_{1-x} alloys is strongly dependent on the current orientation and alloy concentration. An intrinsic mechanism for AMR is found to arise from the band crossing due to magnetization-dependent symmetry protection. These special k points can be shifted towards or away from the Fermi energy by varying the alloy composition and hence the exchange splitting, thus allowing AMR tunability. The prediction is confirmed by delicate transport measurements, which further reveal a reciprocal relationship of the longitudinal and transverse resistivities along different crystal axes.

CircABCB10 silencing inhibits the cell ferroptosis and apoptosis by regulating the miR-326/CCL5 axis in rectal cancer.

Circular ATP binding cassette subfamily B member 10 (circABCB10) has been identified to have oncological functions in several tumors. However, the roles of circABCB10 in rectal cancer remain unknown. The expression of circABCB10, microRNA (miR)-326 and C-C motif chemokine ligand 5 (CCL5), and apoptosis related-protein was detected using quantitative real-time polymerase chain reaction or western blot, respectively. Cell survival or apoptosis was measured using cell counting kit-8 assay or flow cytometry. The accumulations of intracellular lipid reactive oxygen species (ROS) and Fe2+ were analyzed using C11-BODIP dye or iron kit assay, respectively. In vivo experiments were conducted using the murine xenograft model. The interaction between miR-326 and circABCB10 or CCL5 was confirmed by dual-luciferase reporter assay and RNA immunoprecipitation assay. CircABCB10 and CCL5 were upregulated but miR-326 was downregulated in rectal cancer. The knockdown of circABCB10 promoted rectal cancer cell ferroptosis and apoptosis in vitro as well as inhibited tumor growth in vivo. miR-326 was a target of circABCB10, and the miR-326 inhibition could partially attenuate circABCB10 deletion-induced cell ferroptosis and apoptosis. miR-326 directly interacted with CCL5, and the miR-326 inhibition suppressed cell ferroptosis and apoptosis by targeting CCL5. Besides, we observed that miR-326 was negatively regulated by circABCB10, while CCL5 was positively regulated by it, and circABCB10 served as a sponge of miR-326 to regulate the CCL5 expression in rectal cancer cells. CircABCB10 silence promoted rectal cancer cell ferroptosis and apoptosis by regulating the miR-326/CCL5 axis, suggesting a potential therapeutic target for rectal cancer therapy.

Effects of Acute Alcohol Consumption on the Human Brain: Diffusional Kurtosis Imaging and Arterial Spin-Labeling Study.

BACKGROUND AND PURPOSE: Brain function and microstructure are affected by alcohol consumption. Until recently, the effect of alcohol on neural mechanisms has not been fully elucidated. Our aim was to explore the acute effects of alcohol on healthy human brains by diffusional kurtosis imaging and 3D arterial spin-labeling and elucidate structural and functional changes in the brain on acute alcohol intake. MATERIALS AND METHODS: Conventional MR imaging, diffusional kurtosis imaging, and 3D arterial spin-labeling were performed on 24 healthy volunteers before and 0.5 and 1 hour after drinking alcohol. Participants were divided into 2 groups according to the response to alcohol: blushing (n = 12) and unblushing (n = 12) groups. Twenty brain regions were analyzed. RESULTS: Diffusional kurtosis imaging revealed an increase in mean kurtosis and fractional anisotropy at 0.5 hour post-alcohol intake in most brain regions, whereas mean diffusion was decreased in several brain regions at 1 hour after drinking. 3D arterial spin-labeling showed increased cerebral blood flow in most brain regions, particularly in the frontal regions. However, perfusion in the anterior commissure decreased. Regional changes in the brain correlated with various behavioral performances with respect to blush response and sex. In general, blushing individuals and men are more sensitive to alcohol with acute effects. CONCLUSIONS: Physiologic and microstructural alterations in the brain on alcohol consumption were examined. Brain areas with blood flow alteration detected by 3D arterial spin-labeling were highly consistent with susceptible areas detected by diffusional kurtosis imaging. The current study provides new insight into the effects of alcohol on the brain and behavioral performance in different blush response and sex populations.

Absence of Magnetic Thermal Conductivity in the Quantum Spin Liquid Candidate EtMe_{3}Sb[Pd(dmit)_{2}]_{2}.

We present the ultralow-temperature specific heat and thermal conductivity measurements on single crystals of triangular-lattice compound EtMe_{3}Sb[Pd(dmit)_{2}]_{2}, which has long been considered as a gapless quantum spin liquid candidate. In specific heat measurements, a finite linear term is observed, consistent with the previous work [S. Yamashita et al., Nat. Commun. 2, 275 (2011)NCAOBW2041-172310.1038/ncomms1274]. However, we do not observe a finite residual linear term in the thermal conductivity measurements, and the thermal conductivity does not change in a magnetic field of 6 T. These results are in sharp contrast to previous thermal conductivity measurements on EtMe_{3}Sb[Pd(dmit)_{2}]_{2} [M. Yamashita et al., Science 328, 1246 (2010)SCIEAS0036-807510.1126/science.1188200], in which a huge residual linear term was observed and attributed to highly mobile gapless excitations, likely the spinons of a quantum spin liquid. In this context, the true ground state of EtMe_{3}Sb[Pd(dmit)_{2}]_{2} has to be reconsidered.

[Photoelastic analysis of the influence of prosthetic material on the stress distribution in bone around implant].

Objective: To provide a reference for a suitable alternative treatment choice for implant-supported prostheses, and to explore the influence of 3 types of prosthetic material on the stress distribution around implant. Methods: The implant-abutment analogs were embedded individually into photoelastic resin blocks, which were medical pure titanium castings reproducing the surface and outline of implant (diameter 4.3 mm, length 11.5 mm) and esthetic abutment (regular profile, 1 mm). The prostheses were divided into 3 groups according to the type of prosthetic material. Each group consisted of 5 samples. The samples of composite resin ceramic and zirconia group were milled by chair-side computer aided design and computer aided manufacture (CAD/CAM) system. The samples of porcelain-fused-to-metal crown group were made manually and a pre-arranged silicone rubber impression of CAD/CAM crown would guide to shape the veneer porcelain. Each set was submitted to a 300 N compressive load axially or obliquely (75°). The stress value in the peri-implant bone at the level of the neck, neck1/3, middle1/3 and root1/3 of the sections (0.5, 1.5, 2.5, 3.5 mm) from implant was analyzed by digital photoelasticity, and the stress cushioning effect of 3 types of prosthetic material was comprehensively evaluated. Results: The time spent reaching the stress peak of composite resin ceramic group [(1.58±0.08) s, axially; (2.75±0.21) s, obliquely] was larger than that of the zirconia group [(1.40±0.12) s, axially; (2.30±0.25) s, obliquely] (P<0.05) under the same download mode. Although there were no significant differences in equivalent stress values of the measurement points among the three groups (P>0.05), a downward trend of equivalent stress values of composite resin ceramic group was observed compared to zirconia group, regardless of load type. When loaded obliquely, the highest degree of stress concentration at the level of the neck of implant were found in the porcelain-fused-to-metal crown group. Conclusions: Within the limitations of this study, composite resin ceramic was more beneficial to the biomechanical behavior of implant in stress buffer compared to zirconia.

[Effect of nerve growth factor on osteogenic potential of type 2 diabetic mice bone marrow stromal cell in vitro].

Objective: To study the effects of nerve growth factor (NGF) on the proliferation, osteogenic differentiation and mineralization of type 2 diabetic mice bone marrow stromal cell (BMSC), providing basis for clinical application of NGF. Methods: Three 8-week-old male db/db mice and two 8-week-old male C57BL/6J mice were used in the study. BMSC derived from femur were cultured though adherence method. BMSC of C57BL/6J mice and db/db mice was divided into normal group and diabetic group to conduct the osteogenic potential experiment, named experiment one. In experiment two, diabetic BMSC was divided into 3 groups: diabetic control group, NGF group, and K252a+NGF group [K252a was the inhibitor of tyrosine kinase A (TrkA), which was the high affinity receptor of NGF], to investigate effect of NGF on osteogenic potential of diabetic mice BMSC. After seeding BMSC, K252a was added into K252a+NGF group, then NGF was added 30 min later. NGF was added into NGF group and K252a+NGF group, but not diabetic control group. The proliferation of BMSC at 1, 3, 5 and 7 d in experiment one and the proliferation of BMSC at 1, 2 and 3 d in experiment two were evaluated through methyl thiazolyl tetrazolium, and the level of alkaline phosphatase (ALP) at 3, 5 and 7 d in both experiments were measured. After being osteogenic induced for 14 d, mineralized nodules in both experiments were quantitated by alizarin red calcium stain. Five holes were set in every group, and all experiments were repeated 3 times. Results: The BMSC proliferation of diabetic group was significantly higher than that of the normal group at 3, 5 and 7 d (P<0.05). After being osteogenic inducted for 3, 5 and 7 d, ALP level of diabetic group were significantly lower than that of normal group (P<0.05). After being osteogenic inducted for 14 d, calcium nodule count of diabetic group [(23.1±6.4) nodule/field] were significantly lower than that of normal group [(36.9±7.9) nodule/field](P<0.05). At 1, 2 and 3 d, BMSC proliferations of diabetic control group, NGF group and K252a+NGF group were not statistically different (P>0.05). After being osteogenic inducted for 3 and 5 d, ALP level of NGF group was significantly higher than that of diabetic control group (P<0.05). After being osteogenic inducted for 3, 5, and 7 d, ALP level of K252a+NGF group was significantly lower than that of NGF group (P<0.05) and diabetic control group (P<0.05). After being osteogenic induced for 14 d, calcium nodule count of NGF group [(45.2±6.8) nodule/field] was significantly more than that of diabetic control group [(23.1±6.4) nodule/field](P<0.05); while calcium nodule count of K252a+NGF group [(18.0±4.5) nodule/field] was significantly less than that of NGF group (P<0.05) and diabetic control group (P<0.05). Conclusions: The differentiation and mineralization of type 2 diabetic mice BMSC was significantly reduced. NGF promoted the osteoblastic differentiation and mineralization of diabetic mice BMSC in viro though combining with TrkA.

[Effects of intubating laryngeal mask airway in prevention of extubation responses in patients with hypertensive cerebral hemorrhage during general anesthesia recovery period].

OBJECTIVE: To evaluate the effects of intubating laryngeal mask airway (ILMA) in prediction of extubation responses in patients with hypertensive cerebral hemorrhage during general anesthesia recovery period. METHODS: A total of 120 patients with hypertensive cerebral hemorrhage aged 47-71 years, with Glasgow Coma Scale (GCS)11-15 scores and American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, undergoing craniotomy surgery from December 2012 to December 2014 in the Affiliated First Municipal Hospital of Fujian Medical University were randomly divided into 2 groups (n=60): tracheal intubation (Group T) and intubating laryngeal mask airway (Group I), by using a random number table. Variations of invasive arterial blood pressure and responses of endotracheal extubation were compared between two groups before and after extubation. RESULTS: There were no significant differences in ages, sex ratio, preoperative GCS, operation time and the time from the end of operation to Train of Four stimulation (TOF) becoming to 4 between the two groups. The mean arterial pressure (MAP) at the time point of extubation (T3), 1 min (T4), 3 min (T5), 5 min (T6) after extubation were (136±20), (130±16), (128±12), (125±10) mmHg in Group T, and heart rate(HR) at these four time points were (105±11), (96±8), (92±7), (86±6) bpm, respectively. While in group I, MAP were (108±10), (106±8), (105±9), (106±7) mmHg, and HR were (75±8), (76±7), (68±5), (67±6) bpm, respectively. MAP and HR of the two groups at these four time points had significant differences (T3: t=10.91, 17.20; T4: t=13.72, 14.69; T5: t=12.54, 13.35; T6: t=13.39, 11.27; all P<0.01). During recovery, the incidences of extubation responses of group T and group I were 92% and 2%, respectively, and the difference had statistically significant (χ(2)=94.05, P<0.01). The incidences of coughing of group T and group I were 97% and 0, respectively, and the difference had statistically significant (χ(2)=148.69, P<0.01). CONCLUSION: Compared with tracheal intubation, ILMA can decrease the incidence of extubation responses and coughing in patients with hypertensive cerebral hemorrhage during general anesthesia recovery period, and avoid cere-brovascular accidents.

Target replacement strategy for selection of DNA aptamers against the Fc region of mouse IgG.

Aptamers that recognize the IgG Fc region are of great interest because of their wide application as an immunology probing tool, for diagnostics, and as affinity agents for antibody purification. We developed a target replacement strategy as a modification of conventional Systematic Evolution of Ligands by EXponential enrichment (SELEX) in order to efficiently select and identify novel DNA aptamers against the Fc region of mouse IgG. In this new approach, multiple IgG subclasses (IgG1, IgG2a, mouse IgG Fc, and anti-HBs IgG) were sequentially used to select aptamers in one continuous SELEX. After 8 rounds of selection, the aptamers were analyzed using dot blot and an electrophoretic mobility shift assay, which showed universal binding capability to different IgG subclasses. Secondary structure analysis of the aptamers indicated that the stem-loop structure of the aptamers play an important role in binding to the common site in different mouse IgG subclasses. This demonstrated the feasibility of using multiple target replacement SELEX for the selection of aptamers. This target replacement strategy is also expected to be useful for selecting aptamers that bind common regions of molecules other than antibodies.

Metallic single-walled silicon nanotubes.

Atomistic computer-simulation evidences are presented for the possible existence of one-dimensional silicon nanostructures: the square, pentagonal, and hexagonal single-walled silicon nanotubes (SWSNTs). The local geometric structure of the SWSNTs differs from the local tetrahedral structure of cubic diamond silicon, although the coordination number of atoms of the SWSNTs is still fourfold. Ab initio calculations show that the SWSNTs are locally stable in vacuum and have zero band gap, suggesting that the SWSNTs are possibly metals rather than wide-gap semiconductors.

[Clinical analysis of 15 cases with tetramethylenedisulfotetramine].

In our study, we observed the clinical manifestations of 15 tetramethylenedisulfotetramine (TEM) toxicosis emergency patients diagnosed by plasma toxin chemical analysis, and evaluated the effect of emergency treatments. All cases could not be differentiated from the other kinds of toxicosis by clinical manifestations, and toxin chemical analysis was the sole definite diagnosis method. The effect of gastric lavage in early stage was especially obvious, 13 cases with convulsions got immediate relief after plasma exchange, the use of large dosage of tranquilizer resulted in better control on convulsion in 4 cases treated with ventilator than that in the others. Gastric lavage and chemical toxin analysis in early stage are of vital importance, plasma exchange, tracheotomy and mechanical ventilation are the most effective reatment methods.