[Evaluation of the effect of 3D printing resin splint based on the retention effect of orthodontic treatment in patients with periodontal disease].

PURPOSE: To investigate the difference in the retention effect of 3D printing resin splint and Hawley retainer combined with lingual retention wire in periodontal disease patients after orthodontic treatment. METHODS: Forty patients who finished orthodontic treatment for periodontal disease from January 2021 to February 2022 were selected and divided into experimental group and control group according to the random number table method, with 20 patients in each group. Patients in the experimental group used 3D printing resin splint for retention, while patients in the control group used Hawley retainer combined with a lingual retention wire for retention. The chair-side operation time of the retainers was recorded for both groups. The maxillary and mandibular cuspid width, molar width, overjet, overbite and irregularity index were measured at 1 month and 6 months after orthodontic treatment in both groups. Statistical analysis was performed with SPSS 12.0 software package. RESULTS: The mean time for chair-side manipulation of experimental group and control group was 8.23, 11.17 min, respectively. The difference between the two groups was statistically significant (P＜0.05) when comparing the width of the maxillary and mandibular cusps, the width of the molars, overjet, overbite and the irregularity index after 1 month and 6 months of wear of the retainers, which were significantly greater in the experimental group than in the control group at 6 months(P＜0.05). CONCLUSIONS: 3D printing resin splint, with short chair-side manipulation time, was more effective than Hawley retainer combined with a lingual retention wire, and the efficacy of both groups was otherwise generally consistent.

Effect of platelet-rich plasma on the attachment of periodontal ligament fibroblasts to the diseased root surface and the attendant collagen formation.

OBJECTIVE: To investigate the effect of different concentrations of platelet-rich plasma (PRP) on collagen formation via periodontal ligament fibroblasts (PDLFs) on the surface of demineralised diseased tooth roots. METHODS: Various PDLFs were grown from tissue explants, with the cells between the fifth and eighth passage in the culture used. Human whole blood obtained from healthy subjects was collected in tubes containing an anticoagulant (acid-citrate-dextrose) and centrifuged (1300 rpm for 10 min) before the supernatant PRP layer was removed. A second spin at (2000 rpm for 10 min) produced the PRP fraction. The effect of PRP of various concentrations on the attachment of PDLFs on the diseased root surface of human teeth demineralised with ethylenediaminetetraacetic acid (EDTA) and treated with the PRP was then investigated in terms of PRP collagen formation, with the formation observed using the Sirius red staining method. RESULTS: The optical density values of the experimental groups were statistically significantly higher than those of the control groups (P < 0.05), while the Sirius red staining returned positive results for both the experimental group (A) and the control group (B). The images were analysed using a histogram, and a statistically significant difference was found (P < 0.05). CONCLUSION: While PRP could promote the attachment and collagen formation of PDLFs on the diseased root surface of human teeth demineralised with EDTA and treated with PRP, the effect is potentially reduced when the dose exceeds 20%.

[Evaluation of the effect of digital crown extension guide in aesthetic restoration of anterior teeth].

PURPOSE: To evaluate the clinical effect of three-dimensional digital smile design (3D-DSD) combined with double positioning crown extension guide in aesthetic restoration of anterior teeth. METHODS: Twenty patients who needed aesthetic crown lengthening and full crown restoration of upper anterior teeth were selected and randomly divided into the experimental group and control group, with 10 cases in each group. The experimental group carried out 3D-DSD, after confirming the plan, 3D printed double positioning crown extension guides were used to guide aesthetic crown lengthening, and full crown was completed 3 months after operation. The control group used traditional aesthetic crown lengthening and full crown restoration. PES/WES evaluation was performed before operation, three months and six months after operation. Visual analogue scales(VAS) were used to evaluate patient satisfaction 6 and 7 months after surgery, and the repeatability evaluation of VAS was conducted. The correlation between PES/WES score and overall satisfaction was analyzed 6 months after operation. SPSS 23.0 software package was used for statistical analysis. RESULTS: The PES/WES scores of the two groups of patients at 3 months and 6 months after operation were higher than those before operation(P＜0.05). The two groups showed that the scores of the experimental group were significantly higher than those of the control group for PES 3 months after operation, PES and WES 6 months after operation(P＜0.05).Satisfaction survey results showed that the intra-group correlation coefficient of the two VAS results was 0.956(P＜0.05),and crown length-to-width ratio, smile curve, personality characteristics, patient participation and overall satisfaction in the experimental group were better than those of the control group(P＜0.05).The results of Speraman correlation analysis showed that PES and WES scores at 6 months after operation were positively correlated with overall satisfaction (rs1=0.905, P＜0.001; rs2=0.460, P=0.041). CONCLUSIONS: 3D digital smile design combined with double positioning crown extension guide guides the anterior aesthetic crown lengthening and restoration treatment, which can improve the effect of pink and white aesthetics after treatment and patient satisfaction.

Isolated anti-HBc is an independent risk factor for tumor recurrence in intrahepatic cholangiocarcinoma after curative resection.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is a poorly understood and aggressive malignancy with increasing incidence and mortality. Hepatitis B virus (HBV) infection is recognized as one of the important risk factors of ICC. There are few reports focusing on whether isolated antibody to hepatitis B core antigen (isolated anti-HBc, IAHBc) have prognostic role in ICC, while positive hepatitis B surface antigen (HBsAg) has been reported to be associated with the prognosis of ICC. The aim of this study was to investigate the prognostic value of IAHBc in ICC patients after curative resection, in order to identify those who have the high risk of ICC recurrence in the early stage. METHODS: We divided 209 ICC patients who underwent curative resection into 4 groups: group I (n = 40), HBsAg (-)/antibody to hepatitis B surface antigen (anti-HBs) (-)/anti-HBc (+); group II (n = 70), HBsAg (+)/anti-HBc (-); group III (n = 55), HBsAg (-)/anti-HBs (+)/anti-HBc (+); and group IV (n = 44), HBsAg (-)/anti-HBc (-). We compared the recurrence-free survival (RFS) and overall survival (OS) among these four groups. RESULTS: The median follow-up time was 16.93 months (range 1-34.6 months). The 1- and 2-year RFS and OS rates were 60% and 42%, and 78% and 63% respectively in all patients. Compared to the whole non-IAHBc patients (group II + group III + group IV), IAHBc patients (group I) showed significantly lower RFS at 1 year (39.8% vs. 64.4%, P = 0.001) and 2 years (20.7% vs. 46.7%, P = 0.001). When compared to other three individual groups, IAHBc patients (group I) also had the lowest RFS. We did not find significant difference in OS among the four groups. Further multivariate analysis revealed that IAHBc was an independent risk factor of RFS. CONCLUSIONS: IAHBc is an independent poor prognostic factor for tumor recurrence in ICC patients after curative resection.

[Clinical analysis of immune function and intestinal flora changes in patients with oral squamous carcinoma before and after treatment].

PURPOSE: To characterize the alterations of intestinal bacteria and immunological function in patients with oral squamous cell carcinoma(OSCC) before and after treatment. METHODS: From September 2020 to September 2021, 28 patients suffering OSCC and 10 healthy volunteers undergoing treatment at our hospital were enrolled in the study. Conventional treatment regimens were administered to OSCC patients and the changes in immune function, intestinal bacteria composition and short-chain fatty acids were measured 1 week before and 6 months after therapy. GraphPad Prism 9.0 software package was used for data analysis. RESULTS: Immunological function measurements indicated significantly lower levels of lymphocyte subsets (including CD3+, CD4+, NK, CD4+/CD8+) and immunoglobulins (including IgG, IgA, IgM) in the peripheral blood of OSCC patients before treatment compared to healthy volunteers (P<0.05), as well as remarkably lower levels of serum cytokines (including TNF-α、IL-4、IL-6) (P<0.05). Following 6 months of conventional treatment, there was an improvement in immune function in OSCC patients compared to all patients before treatment(P<0.05). Compared to healthy volunteers, the diversity of intestinal bacteria was decreased in OSCC patients before treatment, whereas the diversity of intestinal bacteria recovered in OSCC patients after conventional treatment. At the phylum, the distribution of Epsilonbacteraeota, Proteobacteria and Patescibacteria were significantly elevated and the concentration of Verrucomicrobia was decreased in OSCC patients before treatment compared to healthy volunteers(P<0.05). Intriguingly, convention therapy reversed the disturbance of intestinal bacteria, including downgrading levels of Epsilonbacteraeota, Proteobacteria and Patescibacteria and increasing levels of Verrucomicrobia(P<0.05). Short-chain fatty acids (including acetic acid, propionic acid and butyric acid) were present at a lower level in the intestine of OSCC patients before treatment and were elevated after conventional treatment. CONCLUSIONS: Conventional treatment remarkably enhances immune function, revitalizes the distribution of intestinal microflora, elevates the content of short-chain fatty acids in the intestine of OSCC patients, thereby improving the patients' health.

A theoretical design method for the nozzle pitch of air-flotation system to reduce large liquid crystal display glass substrate's deformation.

The deformation of large glass substrate in air-flotation system affects detection accuracy of inspection instrument. According to the gas lubrication theory, Timoshenko's thin film theory and the simulation figure of the pressure distribution of the air film flow field, the air load distribution model of the air film is established, and the deformation expression of the large liquid crystal glass substrate in air-flotation system is given. On this basis, a theoretical design method for designing nozzle pitch of orifice throttling air-flotation system was proposed. Combined with examples, the results of theories and simulation are compared. An experiment on the deformation of the glass substrate was carried out on an experimental prototype. The difference between the experimental results and the theoretical results does not exceed 10%.

Copper-mediated direct thiolation of aryl C-H bonds with disulfides.

An efficient copper-mediated ortho-C(sp2)-H thiolation of aromatic amides directed by a novel directing group [4-chloro-2-(1H-pyrazol-1-yl)phenyl]amine has been developed without the need of other additives or oxidants, allowing for an increased usefulness. With the high compatibility of sterically demanding substrates, this reaction is scalable and can tolerate a wide scope of functional groups to provide alkyl and aryl thioethers in good to excellent yields (up to 93%). Furthermore, the protocol has been successfully implemented for the selenylation as well.

[Effect of full crown preparation with ultrasound instrument on marginal adaption: a randomized controlled trial].

PURPOSE: To study the effect of full crown ultrasound preparation on crown margin. METHODS: Thirty-two patients with 35 units of full crown were randomly divided into 2 groups. Teeth in the experimental group were prepared with ultrasound diamond instrument while teeth in the control group were prepared with a high-speed hand piece with regular diamond burs. Teeth in both groups were restored using Zirconia full ceramic crowns. Then all patients were evaluated for morphology of finishing line, marginal adaptation and marginal gingival coloration in the proximal side after 6-month of follow-up, respectively. SPSS17.0 software package was used for statistical analysis. RESULTS: Marginal adaptation did not show significant difference between the experimental and control group (P>0.05). Morphology of finishing line and marginal gingival coloration in the proximal side showed significant difference (P<0.05). CONCLUSIONS: It is recommended to perform tooth preparations with ultrasound diamond instruments, which may produce significantly less marginal gingival coloration in the proximal margin after 6-month of follow-up.

Stevens rearrangement of thioethers with arynes: a facile access to multi-substituted ß-keto thioethers.

An effective method for the synthesis of multi-substituted ß-keto thioethers via Stevens rearrangement of simple ß-keto thioethers with arynes has been developed. In these reactions, successive C-S/C-H/C-C bonds were formed in one pot under mild and transition-metal free conditions to afford multi-substituted ß-keto thioethers in moderate to good yields.

Stereospecific Synthesis of Tetrahydronaphtho[2,3-b]furans Enabled by a Nickel-Promoted Tandem Reductive Cyclization.

A Ni-mediated cascade to a stereoselective synthesis of trans-tetrahydronaphtho[2,3-b]furans is efficiently achieved for the first time. The mild reductive system can be easily generated from inexpensive and air-stable materials and shows a broad positional tolerance of substituents that were previously difficult or impossible to access by other methods. Facile syntheses toward new analogues of therapeutic agents (iso)deoxypodophyllotoxin are also reported. In addition, the inherent substrate control is disclosed for the observed unique stereoselectivities during cyclizations.

Preventive Effects of Rhodiola rosea L. on Bleomycin-Induced Pulmonary Fibrosis in Rats.

Rhodiola rosea L. (RRL) possesses a wide range of pharmacological properties, including lung-protective activity, and has been utilized in folk medicine for several 100 years. However, the lung-protective mechanism remains unclear. This study investigated the possible lung-protective activity mechanism of RRL in a pulmonary fibrosis (PF) rat model. Lung fibrotic injury was induced in Sprague-Dawley rats by single intratracheal instillation of saline containing bleomycin (BLM; 5 mg/kg). The rats were administered 125, 250, or 500 mg/kg of a 95% ethanol extract of RRL for 28 days. The animals were killed to detect changes in body weight, serum levels of glutathione (GSH) and total superoxide dismutase (T-SOD), as well as lung tissue hydroxyproline (HYP) content. Tumor necrosis factor-α (TNF-α), transforming growth factor-ß1 (TGF-ß1), and interleukin 6 (IL-6) levels were measured in bronchoalveolar lavage fluid (BALF) by enzyme-linked immunosorbent assay. Hematoxylin and eosin, Masson's trichrome, and immunohistochemical staining were performed to observe the histopathological changes in lung tissues. Additionally, target-related proteins were measured by Western blotting. RRL alleviated the loss of body weight induced by instilling BLM in PF rats, particularly at the 500 mg/kg per day dose. RRL reduced HYP (p < 0.01) and increased GSH and T-SOD contents. BALF levels of TNF-α, TGF-ß1, and IL-6 decreased significantly in the RRL-treated groups. Expression levels of matrix metalloproteinase-9 (MMP-9) and α-smooth muscle actin decreased significantly in a dose-dependent manner in response to RRL. Moreover, the levels of TGF-ß1 and tissue inhibitor of metalloproteinase-1 in lung tissues also decreased in the RRL-treated groups. RRL alleviated BLM-induced PF in rats. Our results reveal that the protective effects of RRL against fibrotic lung injury in rats are correlated with its anti-inflammatory, antioxidative, and anti-fibrotic properties. MMP-9 may play important roles in BLM-induced PF.

Autoimmune pancreatitis associated with a pancreatic pseudocyst treated by distal pancreatectomy with splenectomy: case report.

Autoimmune pancreatitis is a unique type of chronic pancreatitis, which is rarely associated with pseudocyst. A 48-year-old lady was admitted to our department with a rapidly growing cystic mass in the pancreatic tail with an elevated concentration of serum carbohydrate antigen 19-9 (CA19-9). She had a history of autoimmune pancreatitis and received steroid treatment. Imaging studies demonstrated a cystic mass in the pancreatic tail. The mass kept growing despite restoration of steroid treatment. Eventually, the patient underwent distal pancreatectomy with splenectomy. Histopathological examination revealed the existence of pseudocyst, significant lymphocytic infiltration, and fibrotic change in the pancreatic tail.

Nickel-mediated stereocontrolled synthesis of spiroketals via tandem cyclization-coupling of ß-bromo ketals and aryl iodides.

A ketal-tether approach for the stereoselective synthesis of [5,5] and [5,6]-spiroketals based on reductive coupling catalyzed by the readily available Ni complex is demonstrated. Either an intermolecular or an intramolecular stereospecific cascade has been achieved as well.

Total synthesis of (±)-sacidumlignans D and A through Ueno-Stork radical cyclization reaction.

Efficient synthesis of (±)-sacidumlignan D (4) has been successfully achieved employing Ueno-Stork radical cyclization of α-bromo acetal 21 as a key step. Two synthetic approaches for the symmetrical diaryl ketone 19 have been discussed in detail. Notably, sacidumlignan A (1) can be also efficiently synthesized in only 7 steps with 25% overall yield, where acid triggered tandem reaction starting from analogous Ueno-Stork cyclization product 27 played an important role. Moreover, potentially biomimetic conversion from (±)-sacidumlignan D (4) to sacidumlignan A (1) could be realized.

Nickel-mediated inter- and intramolecular C-S coupling of thiols and thioacetates with aryl iodides at room temperature.

A Ni(0)-catalyzed intermolecular cross-coupling of various functionalized thiols and aryl iodides has been developed and successfully extended to less explored intramolecular versions, where thioacetates could also be utilized as the strategic surrogate. Air-stable precatalysts, very mild conditions, and an easy protocol allow rapid access to medicinally useful aryl thioethers, as demonstrated in the facile synthesis of (±)-chuangxinmycin as a key step.

Null genotype of GSTM1 and GSTT1 may contribute to susceptibility to male infertility with impaired spermatogenesis in Chinese population.

Glutathione-S-transferases (GSTs) play a protective role during spermatogenesis and GST genes may be involved in impaired spermatogenesis. A case-control study was performed to explore the association of genes GSTM1 and GSTT1, two members of GST gene family, with spermatogenesis impairment. The deletion polymorphism distribution of genes GSTM1 and GSTT1 was investigated in 353 patients with azoospermia or oligospermia and 201 fertile controls in Chinese population using multiplex PCR. As a result, the frequencies of null genotype of genes GSTM1 (67.4% versus 57.7%, p = 0.022, OR = 1.516, 95% CI = 1.001-2.168) and GSTT1 (61.8% versus 46.8%, p = 0.001, OR = 1.838, 95% CI = 1.295-2.610) in patients were significantly higher than those in controls. After stratifying patients, the frequencies of null genotype of gene GSTM1 in oligospermia (68.3% versus 57.7%, p = 0.027, OR = 1.580, 95% CI = 1.051-2.375) and GSTT1 in azoospermia (66.9% versus 46.8%, p < 0.001, OR = 2.299, 95% CI = 1.484-3.562) as well as oligospermia (57.9% versus 46.8%, p = 0.025, OR = 1.567, 95% CI = 1.057-2.322) were still significantly higher compared with controls. The results suggested that null genotypes of GSTM1 and GSTT1 are associated with spermatogenesis impairment and may contribute to susceptibility to spermatogenesis impairment and male infertility in Chinese population.

Nickel-mediated inter- and intramolecular reductive cross-coupling of unactivated alkyl bromides and aryl iodides at room temperature.

A nickel-mediated intermolecular reductive cross-coupling reaction of unactivated alkyl bromides and aryl iodides at room temperature has been developed and successfully extended to less explored intramolecular versions and tandem cyclization-intermolecular cross-coupling. Highly stereoselective (or stereospecific) synthesis of linear-fused perhydrofuro[2,3-b]furan (pyran) and spiroketal skeletons allows rapid access to these useful building blocks, which would be potentially valuable in the synthesis of relevant natural products. A rational explanation for the formation of contiguous stereogenic centers is given.

Prevalence of and risk factors for subjective symptoms in urban preschool children without a cause identified by the guardian.

OBJECTIVE: The aim of this study was to explore the prevalence of and the risk factors for subjective symptoms without an identified cause by the guardian (SSWICG) in urban preschool children. METHODS: A questionnaire was used to collect information from 661 urban preschool children. The subjective symptoms were cited from the MM075NA Indoor Environment Quality Investigation Questionnaire. Information about living conditions, kindergarten and outdoor environments was collected, as well as health information from each child. RESULTS: The prevalence of SSWICG reached 31%, among which the prevalence of general symptoms in the central nervous system (CNS) reached 54.6%. Univariate analysis showed that the materials that made indoor furniture, walls and doors, indoor biological factors, outdoor pollution sources near the house and traffic pollution were associated with SSWICG and mucosal, dermal and general symptoms in the CNS subgroups. Multivariate analysis also showed that furniture materials, traffic pollution, kindergarten environment quality and allergies were associated. CONCLUSIONS: The prevalence of SSWICG was relatively high. Possible risk factors include indoor furnishing materials, allergy, traffic pollution and kindergarten environmental pollution.

Tetrabutyl titanate-controlled polymerization of epsilon-caprolactone at ambient temperature.

A low cost and environmentally benign process for tetrabutyl titanate-controlled ring-opening polymerization of epsilon-caprolactone at ambient temperature of 10-40 degrees C is introduced affording poly(epsilon-caprolactone) with pre-designed molecular weights and narrow molecular weight distribution.

[Change of unsaturated fatty acids in hippocampus of mice exposed to lead].

OBJECTIVE: To study possible impairment mechanisms of learning and memory abilities from unsaturated fatty acids in hippocampus of mice exposed to lead. METHODS: Forty-eight healthy mice were divided into 4 groups: low dose (0.625 g/L), middle dose (1.250 g/L) and high dose (2.500 g/L) of lead solution in diet and control group (distilled water). The mice in treatment groups were fed with lead solution every day while the mice in control group were fed with distilled water for 50 days. After learning and memory abilities were measured, the mice were killed and contents of oleic acid (C18:1), linoleic acid (C18:2), linolenic acid (C18:3), arachidonic acid (AA,C20:4), eicosapentaenoic acid (EPA,C20:5) and docosahexaenoic acid (DHA, C22:6 ) in hippocampus of mice were determined by high performance liquid chromatography (HPLC). RESULTS: (1) In the four training days, the mice treated with lead in the middle dose group and high dose group significantly increased the escape latencies compared with the mice treated with distilled water (P<0.05), and on the 4th day, the low dosage mice's escape latencies were delayed (P<0.05). The escape latencies of the 1st, 2nd, 3rd and 4th day had significantly positive linear relation with lead dose. Their relative coefficient in turn is r=0.973, 0.985, 0.929 and 0.936, indicating that lead harmed spatial memory of mice in Morris water maze (MWM). (2) The contents of C18:2 and AA were obviously enhanced in hippocampus of middle and high dosage (P<0.05); while there was evident decrease in the contents of C18:3, EPA and DHA (P<0.05); the content of C18:1 was decreased significantly in high dosage group (P<0.01). The mice's escape latencies had significantly negative linear relation with contents of C18:1, C18:3, EPA and DHA, while there was positive linear relation significantly with contents of C18:2 and AA. Their relative coefficient in turn was r=-0.901, -0.914, -0.893, -0.855, 0.936, 0.727. CONCLUSION: Lead interferes with the metabolism of hippocampus fatty acids and affects membrane function in hippocampus of mice, which might contribute to change of the synthesis, metabolism and release of central neurotransmitter and decrease of the learning and memory abilities.