[Clinical study of locking-taper implants in patients treated for periodontitis]

OBJECTIVE

To evaluate the survival rate and peri-implant clinical parameters of Locking-Taper implants in patients having lost their teeth due to non-periodontitis (NP) reasons, chronic periodontitis (CP) and aggressive periodontitis (AgP).

METHODS

In the study, 145 subjects were installed with 315 Bicon Locking-Taper implants and followed up for 1-5 years. The subjects and implants were classified into three groups, tooth loss by NP, CP and AgP. NP included 44 subjects with 100 implants, CP 70 subjects with 132 implants and AgP 31 subjects with 83 implants. Periodontal parameters before subgingival scaling and root planning (T0), at the end of active periodontal therapy (T1) and at the time of last recall (T2) were recorded. Right after the installation of final restoration and at the time of last recall (T2), peri-implant probing parameters were recorded.

RESULTS

After active periodontal therapy, mean probing depth (PD) in CP and AgP were reduced from 4.05 mm, 5.20 mm at T0 to 3.07 mm, 2.96 mm at T1 (P<0.001, P<0.001), (PD≥6 mm)% were reduced from 33.2%, 58.5% at T0 to 14.4%, 10.5% at T1 (P<0.001, P<0.001). The periodontal parameters remained stable at T2 compared with T1 (P>0.05). Cumulative survival rates of implants in NP, CP and AgP were 100%, 97.6% and 100% for 1-5 years' follow-ups with no statistical significance found. At T2, mean implant PD was 2.78 mm, 2.96 mm and 2.97 mm in NP, CP and AgP, with NP significantly lower than the other two groups (P=0.006, P=0.01). The percentage of implant sites with PD≥6 mm was 3.7% in CP and 4.8% in AgP, both significantly higher than NP (P=0.003, P<0.001). 8.4% implant sites showed at least 2 mm deeper than those at prosthesis installation were found in CP group, significantly higher than NP (4.3%, P=0.003).

CONCLUSION

Periodontal conditions of patients having lost their teeth for chronic and aggressive periodontitis were significantly improved after active periodontal therapy and remained stable during 1-5 years. Short-term survival rates of Locking-Taper implants in patients treated for CP and AgP was no less than those who lost their teeth for non-periodontitis reasons. More sites with increasing peri-implant probing depth were found in CP and AgP patients, compared with NP.

[Applied research of "quadri-low" combined with automatic tube current modulation and iterative model reconstruction technology in head and neck CT angiography]

Objective: To investigate the feasibility of low tube voltage, low contrast medium concentration, injection rate and volume (quadri-low) combined with automatic tube current modulation (ATCM) and iterative model reconstruction (IMR) technology in head and neck CT angiography (CTA). Methods: A total of 70 patients whose body mass index (BMI)<25 kg/m(2) underwent head and neck CTA and digital subtraction angiography (DSA) from January to July 2017 were enrolled in this prospective study. According to random number table, patients were divided into two groups: group A (n=35) was scanned according to the protocol of 120 kV, 150 mAs, 50 ml and 5 ml/s iopromide (370 mg/ml) and filtered back projection (FBP) reconstruction; group B (n=35) was scanned with 80 kV, ATCM with mean tube current of 100 mAs, 30 ml and 3 ml/s iohexol (300 mg/ml) and IMR; the other parameters kept consistent between the two groups. The maximum transverse neck diameter at the level of the hyoid bone, artery CT value and image noise were measured, signal to noise ratio (SNR), contrast to noise ratio (CNR) and figure of merit (FOM) were calculated, and the image quality was evaluated subjectively and compared with those reconstructed by DSA. Scan length, volume CT dose index (CTDIvol) and dose length product (DLP) were recorded, and the effective dose (ED) was calculated. The chi-square and independent-sample t tests were used to compare the inter-group differences in these aforementioned data. Resutls: No significant difference was found in general information between the two groups. No significant difference existed in artery CT value, image noise, SNR and CNR between the two groups (t=-1.170-1.365, all P>0.05); however, the FOM of group B (74±40) was significantly higher than that in group A (12±4) (Z=-7.195, P=0.000). The image quality of the two groups met the requirement of clinical diagnosis[(4.1±0.7) vs (4.2±0.8) points, Z=-0.592, P>0.05], no significant difference was found in subjective evaluation and diagnostic efficacy. The CTDIvol, DLP and ED in group B were all significantly lower than those in group A (Z=-7.728, -7.202, -7.206, all P<0.05). The iodine load and iodine delivery rate (IDR) of group B was lower than that of group A (18.5 g vs 9.0 g, 1.85 mg/s vs 0.90 mg/s), and they were reduced for 51.4% in group B. Conclusions: For patients of BMI <25 kg/m(2,) low tube voltage, low contrast medium concentration, injection rate and volume combined with ATCM and IMR technology can significantly decrease radiation dose, iodine load and IDR while maintain the image quality in head and neck CTA examination.

Discrepancy of Clinical Parameters between the First and Second Molars Can Help to Differentiate Subjects with Aggressive Periodontitis from Chronic Periodontitis: a Cross-sectional Study Based on a Large Chinese Population

OBJECTIVE

To explore associations between mean discrepancy values for the first and second molars (MDVFSs) and generalised aggressive periodontitis (GAgP) using hospital-based periodontal examination records from a large Chinese population.

METHODS

Data from consecutive patients diagnosed as having chronic periodontitis (CP, n = 51,849) and GAgP (n = 2,706) were included. Patient ages, gender, smoking status, mean full-mouth probing depth (PD), and mean full-mouth attachment loss (AL), as well as MDVFSs for PD and AL, were extracted. Multivariate linear regression was used to test associations between MDVFSs and GAgP.

RESULTS

After multivariate risk adjustment for potential confounding factors (age, smoking status, and mean PD and AL), the MDVFSs for PD (OR = 2.20, 95%CI: 2.04 to 2.38, P < 0.001) and AL (OR = 1.51, 95CI%: 1.44 to 1.59, P < 0.001) were significantly associated with GAgP. The probability of GAgP was associated with MDVFS for PD falling between 0 mm and 2.5 mm (OR = 4.55, 95%CI: 4.01 to 5.17) and MDVFS for AL falling between 0 mm and 3.5 mm (OR = 2.01, 95%CI: 1.86 to 2.16, P < 0.001).

CONCLUSION

This study revealed associations between MDVFSs and GAgP, demonstrating that MDVFSs can serve as promising auxiliary references for the differential diagnosis between CP and GAgP.

A G3P[13] porcine group A rotavirus emerging in China is a reassortant and a natural recombinant in the VP4 gene

Group A rotaviruses (RVAs) are a major cause of serious intestinal disease in piglets. In this study, a novel pig strain was identified in a stool sample from China. The strain was designated RVA/Pig/China/LNCY/2016/G3P[13] and had a G3-P[13]-I5-R1-C1-M1-A8-N1-T1-E1-H1 genome. The viral protein 7 (VP7) and non-structural protein 4 (NSP4) genes of RVA/Pig/China/LNCY/2016/G3P[13] were closely related to cogent genes of human RVAs, suggesting that a reassortment between pig and human strains had occurred. Recombination analysis showed that RVA/Pig/China/LNCY/2016/G3P[13] is a natural recombinant strain between the P[23] and P[7] RVA strains, and crossover points for recombination were found at nucleotides (nt) 456 and 804 of the VP4 gene. Elucidating the biological characteristics of porcine rotavirus (PoRV) will be helpful for further analyses of the epidemic characteristics of this virus. The results of this study provide valuable information for RVA recombination and evolution and will facilitate future investigations into the molecular pathogenesis of RVAs.

Correlative factors' analysis of postural-related ocular cyclotorsion with image-guided system

PURPOSE

To explore the correlation between ocular cyclotorsion induced by sitting and supine positions as well as other selected factors, validated by an image-guided system.

STUDY DESIGN

A cross-sectional study conducted in 73 inpatients (85 eyes) who received intraocular operations in China Medical University.

METHODS

The ocular cyclotorsion degree was recorded using an image-guided system (Verion Reference Unit, Alcon) by comparing images captured in sitting position, as well as pre- and post-different anesthesia methods in the supine position. Possible correlative factors including age, gender, eye axial length, best corrected visual acuity (BCVA), astigmatism degree, astigmatism axis, anesthesia, and comparison in laterality of eyes on ocular cyclotorsion were analyzed.

RESULTS

The total cyclotorsion rate was 88.24% and the cyclotorsion degree ranged from - 14.0° to + 12.0° with an average of 4.6° ± 3.4°. Excyclotorsion was predominant OD whereas incyclotorsion was predominant OS (p < 0.05). The effect of eye axial length, BCVA, astigmatism degree, astigmatism axis, anesthesia method, age and gender on cyclotorsion orientation was not statistically significant, neither did these factors show any significant differences in the ocular cyclotorsion degree (p > 0.05). Pre- and post-anesthesia, and different anesthetic methods, did not show any significant influence on the ocular cyclotorsion degree (p > 0.05).

CONCLUSIONS

Cyclotorsion orientation seems to be correlated only with eye laterality. None of the other investigated factors, including age, gender, eye axial length, BCVA, astigmatism degree, astigmatism axis and anesthesia seems to affect cyclotorsion orientation or degree.

DNA methylation and expression of imprinted genes are associated with the viability of different sexual cloned buffaloes

The DNA methylation of imprinted genes is an important way to regulate epigenetic reprogramming of donor cells in somatic cell nuclear transfer (SCNT). However, the effects of sexual distinction on the DNA methylation of imprinted genes in cloned animals have seldom been reported. In this study, we analysed the DNA methylation status of three imprinted genes (Xist, IGF2 and H19) from liveborn cloned buffaloes (L group, three female and three male), stillborn cloned buffaloes (S group, three female and three male) and natural reproduction buffaloes (N group, three female and three male), using bisulphite sequencing polymerase chain reaction (BS-PCR). The expression levels of these imprinted genes were also investigated by quantitative real-time PCR (QRT-PCR). The DNA methylation levels of H19 were not significantly different among the groups. However, the Xist in female and IGF2 in male of the S group were found to be significantly hypomethylated in comparison with the same sexual buffaloes in L group and N group (p < .05). Furthermore, the expression levels of Xist, IGF2 and H19 in the stillborn female cloned buffaloes of S group were significantly higher than that of the female buffaloes in the L group and N group (p < .05). The expression levels of IGF2 and H19 in the stillborn male cloned buffaloes in the S group were significantly higher than that of the male buffaloes in the L group and N group (p < .05). These results indicate that Xist may be associated with the viability of female cloned buffaloes, and IGF2 may also be related to the viability of male cloned buffaloes.

Feasibility study of iterative model reconstruction combined with low tube voltage, low iodine load, and low iodine delivery rate in craniocervical CT angiography

AIM

To investigate the feasibility of iterative model reconstruction (IMR) combined with low tube voltage, low iodine load, and low iodine deliver rate in craniocervical computed tomography angiography (CTA).

MATERIALS AND METHODS

Sixty patients were randomly divided into two groups (n=30 for each): group A: 120 kVp, 50 ml of iopromide at a flow rate of 5 ml/s; filtered back projection (FBP) reconstruction; group B: 80 kVp, 30 ml of iohexol at 4.5 ml/s; hybrid iterative reconstruction (HIR) for group B1 and IMR for group B2. CT attenuation values, image noise, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), subjective image quality, effective dose (ED), iodine load, and iodine delivery rate (IDR) were compared.

RESULTS

CT attenuation values of the arteries were higher in groups B1 and B2 than group A. The SNR and CNR were higher, while image noise was lower, for group B2 compared with groups B1 and A. The best subjective image quality was obtained with group B2. ED, iodine load, and IDR reduction of 69.6%, 51.4%, 27%, respectively, was obtained in group B compared with group A.

CONCLUSION

IMR combined with 80 kVp and 30 ml of iohexol at a flow rate of 4.5 ml/s for craniocervical CTA can reduce ED, iodine load, and IDR, while improving image quality.

Enhanced blood brain barrier permeability and glioblastoma cell targeting via thermoresponsive lipid nanoparticles

Thermoresponsive targeting is used to deliver therapeutic agents at hyperthermic conditions (39-45 °C). However, available thermoresponsive drug delivery systems (TDDS), including liposomes, have a complex method of preparation involving toxic solvents and reagents. The objective of this in vitro study was to prepare and characterize thermoresponsive lipid nanoparticles (TLN) for treating glioblastoma, the most aggressive brain tumor whose treatment is limited by a low blood brain barrier (BBB) permeability of drugs. Thermoresponsive lipids were prepared by mixing liquid and solid fatty acids (0.1 : 1 to 2 : 1 ratio) and lipid mixtures exhibiting a solid-liquid phase transition at 39 °C were identified by plotting melting point against liquid contents. TLN were prepared by a hot melt encapsulation method using mono- or double-surfactant systems. TLN showed desirable size (<270 nm), zeta potential (-35 to -50 mV), spherical morphology and stability by FTIR studies. In the drug release studies, paclitaxel release was slow at 37 °C, however, it was released abruptly at 39 °C due to the faster diffusion rate from liquid state nanoparticles. During cytotoxicity studies, the unloaded TLN were non-toxic whereas paclitaxel loaded TLN showed higher cytotoxicity to glioblastoma cells at 39 °C (69% cell viability after one hour) compared to 37 °C (82% cell viability). The TLN showed higher permeability across an in vitro model of BBB at 39 °C due to a deformable liquid state which can squeeze through the tight junctions of the BBB. In conclusion, this study demonstrated that the TLN can be used as a safe and effective alternative to traditional TDDS with higher potential to target glioblastoma cells across the BBB.

FTY720 ameliorates renal fibrosis by simultaneously affecting leucocyte recruitment and TGF-β signalling in fibroblasts

Renal fibrosis is the common final manifestation of chronic kidney diseases and usually results in end-stage renal failure. In this study, we evaluated the effect of fingolimod (FTY720), an analogue of sphingosine 1-phosphate (S1P), as a treatment for the unilateral ureteral obstruction (UUO)-induced renal fibrosis animal model. We treated mice with FTY720 at a dosage of 1 mg/kg/day by intragastric administration from day 1 until day 7. The control group received the same amount of saline. FTY720 reduced significantly the urine albumin/creatinine ratio (UACR) in treated UUO mice. FTY720 treatment also caused a significant decrease in interstitial expansion and collagen deposition in the kidney, accompanied by reduced mononuclear cell recruitment and inflammatory cytokine expression. In addition, the expression levels of the endothelial cell adhesion molecules P-selectin and vascular cell adhesion protein 1 (VCAM-1) were suppressed in the ligated kidney by FTY720 administration, suggesting reduced renal endothelial cell activation. Furthermore, in renal interstitial fibroblast normal rat kidney (NRK)-49F cells, FTY720 significantly affected transforming growth factor (TGF)-β-induced α-smooth muscle actin (SMA) expression and collagen synthesis by inhibiting both the Mothers against decapentaplegic homologue (Smad)2/3 and phosphatidylinositol 3-kinase/protein kinase B/glycogen synthase kinase 3 beta (PI3K/AKT/GSK3β) signalling pathways. S1P1 knock-down by siRNA reversed this effect significantly in our fibroblast cell culture model. Therefore, FTY720 attenuates renal fibrosis via two different mechanisms: first, FTY720 suppresses the synthesis of extracellular matrix in interstitial fibroblasts by interfering with TGF-β signalling; and secondly, FTY720 affects endothelial cell activation and chemokine expression, thereby reducing immune cell recruitment into the kidney.

[Clinical application value and imaging diagnosis of stress fracture]

OBJECTIVE

To discuss the imaging findings of stress fracture, in order to improve the ability of early diagnosis and early treatment of this disease.

METHODS

The DR, CT and MRI imaging data of 336 cases of stress fracture from January 2010 to January 2016 were analyzed retrospectively. Early diagnosis ratio in stress fractures by three methods were analyzed using χ²-test.

RESULTS

Early diagnosis ratio of three methods as follow: DR was 70.83%(238/332), CT was 55.93%(66/118), and MRI was 73.61%(53/72). There was statistical significance among three methods (χ²=10.15, P=0.006), the early diagnosis ratio of DR was higher than CT (χ²=8.765, P=0.003)and there was no statistical significance between DR and MRI (χ²=0.224, P=0.636).

CONCLUSIONS

DR and MRI have better diagnosis of stress fractures while CT is not helpful in the early diagnosis. DR examination is preferred method due to its economical and convenient. MR is the important complement means, which can improve the early diagnosis ratio and provide imaging diagnosis basis for the clinical, so that the disease get early intervention and treatment.

ORF3a deletion in field strains of porcine-transmissible gastroenteritis virus in China: A hint of association with porcine respiratory coronavirus

Porcine‐transmissible gastroenteritis virus (TGEV) is a pathogenic coronavirus responsible for high diarrhoea‐associated morbidity and mortality in suckling piglets. We analysed the TGEV ORF3 gene using nested polymerase chain reaction and identified an ORF3a deletion in three field strains of TGEV collected from piglets in China in 2015. Eight TGEV ORF3 sequences were obtained in this study. Phylogenetic tree analysis of ORF3 showed that the eight TGEV ORF3 genes all belonged to the Miller cluster. CH‐LNCT and CH‐MZL were closely correlated with Miller M6, while CH‐SH was correlated with Miller M60. These results thus indicate that the existence of Miller, as well as the Purdue cluster, in Chinese field strains of TGEV. Furthermore, we found the first evidence for a large deletion in ORF3 resulting in the loss of ORF3a, previously reported in porcine respiratory coronavirus, in three field strains (CH‐LNCT, CH‐MZL, and CH‐SH) of TGEV. The results of the present study thus provide important information regarding the underlying evolution mechanisms of coronaviruses.

Thermoplastic High Strain Multishape Memory Polymer: Side-Chain Polynorbornene with Columnar Liquid Crystalline Phase

A thermoplastic high strain multishape memory polymer can be fabricated using a hemiphasmid side-chain polynorbornene (P1) with hexagonal columnar liquid crystalline (Φ_H ) phase. Without any chemical crosslinks, P1 can memorize multiple temporary shapes with high strain and exhibit excellent shape fixity and shape recovery. As the building blocks of Φ_H , the multichain columns in P1 act as robust physical crosslinks.

Tetramethoxy-Aminorhodamine (TMARh): A Bichromophore, an Improved Fluorophore, and a pH Switch

Rhodamine is one of the most widely used fluorescent dyes. Here, a new synthetic pathway to the popular dyes is reported and the effect of adding four methoxy groups to the molecular structure is investigated. Tetramethoxy-aminorhodamine (TMARh) is found to show superior pH switching compared to the rhodamine without the four methoxy groups, owing to changed properties of the dark "off" state and increased fluorescence intensity in the protonated "on" state.

Solution-Grown Monocrystalline Hybrid Perovskite Films for Hole-Transporter-Free Solar Cells

High-quality perovskite monocrystalline films are successfully grown through cavitation-triggered asymmetric crystallization. These films enable a simple cell structure, ITO/CH3 NH3 PbBr3 /Au, with near 100% internal quantum efficiency, promising power conversion efficiencies (PCEs) >5%, and superior stability for prototype cells. Furthermore, the monocrystalline devices using a hole-transporter-free structure yield PCEs ≈6.5%, the highest among other similar-structured CH3 NH3 PbBr3 solar cells to date.

The In-Gap Electronic State Spectrum of Methylammonium Lead Iodide Single-Crystal Perovskites

The density of trap states within the bandgap of methylammonium lead iodide single crystals is investigated. Defect states close to both the conduction and valence bands are probed. Additionally, a comprehensive electronic characterization of crystals is carried out, including measurements of the electron and hole mobility, and the energy landscape (band diagram) at the surface.

Reduced Field-of-View Diffusion Tensor Imaging of the Optic Nerve in Retinitis Pigmentosa at 3T

BACKGROUND AND PURPOSE

Diffusion tensor imaging may reflect pathology of the optic nerve; however, the ability of DTI to evaluate alterations of the optic nerve in retinitis pigmentosa has not yet been assessed, to our knowledge. The aim of this study was to investigate the diagnostic potential of reduced FOV-DTI in optic neuropathy of retinitis pigmentosa at 3T.

MATERIALS AND METHODS

Thirty-eight patients and thirty-five healthy controls were enrolled in this study. Measures of visual field and visual acuity of both eyes in all subjects were performed. A reduced FOV-DTI sequence was used to derive fractional anisotropy, apparent diffusion coefficient, principal eigenvalue, and orthogonal eigenvalue of the individual optic nerves. Mean fractional anisotropy, ADC, and eigenvalue maps were obtained for quantitative analysis. Further analyses were performed to determine the correlation of fractional anisotropy, ADC, principal eigenvalue, and orthogonal eigenvalue with optic nerves in patients with mean deviation of the visual field and visual acuity, respectively.

RESULTS

The optic nerves of patients with retinitis pigmentosa compared with control subjects showed significantly higher ADC, principal eigenvalue, and orthogonal eigenvalue and significantly lower fractional anisotropy (P < .01). For patients with retinitis pigmentosa, the mean deviation of the visual field of the optic nerve was significantly correlated with mean fractional anisotropy (r = 0.364, P = .001) and orthogonal eigenvalue (r = -0.254, P = .029), but it was not correlated with mean ADC (P = .154) and principal eigenvalue (P = .337). Moreover, no correlation between any DTI parameter and visual acuity in patients with retinitis pigmentosa was observed (P > .05).

CONCLUSIONS

Reduced FOV-DTI measurement of the optic nerve may serve as a biomarker of axonal and myelin damage in optic neuropathy for patients with retinitis pigmentosa.

Spiro-OMeTAD single crystals: Remarkably enhanced charge-carrier transport via mesoscale ordering

We report the crystal structure and hole-transport mechanism in spiro-OMeTAD [2,2',7,7'-tetrakis(N,N-di-p-methoxyphenyl-amine)9,9'-spirobifluorene], the dominant hole-transporting material in perovskite and solid-state dye-sensitized solar cells. Despite spiro-OMeTAD's paramount role in such devices, its crystal structure was unknown because of highly disordered solution-processed films; the hole-transport pathways remained ill-defined and the charge carrier mobilities were low, posing a major bottleneck for advancing cell efficiencies. We devised an antisolvent crystallization strategy to grow single crystals of spiro-OMeTAD, which allowed us to experimentally elucidate its molecular packing and transport properties. Electronic structure calculations enabled us to map spiro-OMeTAD's intermolecular charge-hopping pathways. Promisingly, single-crystal mobilities were found to exceed their thin-film counterparts by three orders of magnitude. Our findings underscore mesoscale ordering as a key strategy to achieving breakthroughs in hole-transport material engineering of solar cells.