The 3D-printed Ti-6Al-4V intervertebral fusion cage is fabricated to be biocompatible with improved stiffness, fatigue life, and osteogenic differentiation, which are greatly enhanced by heat ...treatment and surface modification. The flexible cage’s life, which exceeds the standard dynamic fatigue requirement of 5 × 106 cycles based on the ASTM F2077 and F2267 test methods, is achieved by heat treatment at 800 ℃ in argon atmosphere, shot peening, and adjusting the α to β phase ratio to increase mechanical toughness. Surface modification via sandblasting and chemical etching removes the surface oxide layer and forms submicron pores on the surface of the cage, which significantly boosts cell proliferation, differentiation, and osteoblast mineralization. This work exhibits a novel design of Ti-6Al-4V intervertebral fusion cage with biocompatible stiffness, enhanced fatigue life, and improved osteogenic differentiation achieved by reducing residual stress, modifying surface micro-pores, and optimizing microstructure.
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•Ti-6Al-4V intervertebral cage with biocompatible stiffness, enhanced fatigue life, and improved osteogenic differentiation.•Heat treatment and shot peening to adjust residual stress and optimizing microstructure to increase mechanical toughness.•Sandblasting and chemical etching boost cell proliferation, differentiation, and osteoblast mineralization.
•Hydatidiform moles have different risks for gestational trophoblastic disease.•Hydatidiform moles cannot be diagnosed by histologic examination alone.•Loss of p57 occurs in all complete moles but ...not in partial moles.•Ploidy analysis could be useful for the classification of hydatidiform moles.•High frequency of chromosomal abnormality occurs in hydropic abortion.
Discrimination between complete moles (CMs), partial moles (PMs), and hydropic abortions (HAs) is important as the risk of persistent gestational trophoblastic disease (GTD) differs for each condition. We evaluated whether ancillary fluorescence in situ hybridization (FISH) with a set of chromosome enumeration probes (CEP) for chromosomes X, Y, and 17 and p57 immunostaining could improve the clinical diagnosis. Forty-one products of conception (POC) were reclassified according to clinical performance, morphology, p57 immunostaining results, and FISH results. The accuracy of histological examination alone was 85% for the original diagnosis. FISH analysis showed diploidy in 19 of 20 CMs and triploidy in 4 of 6 PMs. The concordance rate was 92.5% on using the CEP probes. p57 Staining was negative in all CMs and positive in all PMs and HAs. Chromosomal abnormality was detected in 3 cases of HA by using FISH. In conclusion, combined p57 immunostaining and FISH with a set of 3 CEP probes for chromosomes X, Y, and 17 could be useful in the classification of hydatidiform moles.
BACKGROUND: The pyrethroids cypermethrin and cis-bifenthrin are the major pesticides used in tea plantations in China. Potential neurotoxic, genotoxic and immunotoxic effects of chronic exposure to ...pyrethroids have been reported. All synthetic pyrethroids are chiral compounds. There is a need to investigate the chiral transformation among isomers after tea processing in order to obtain an accurate risk assessment of these compounds.RESULTS: The enantiomeric fraction (EF) of cis-bifenthrin residues was close to 0.5 in all tea samples tested, showing that the levels of (+)-isomer and (-)-isomer were equivalent and there was no preferential degradation. However, the patterns of EFs of cypermethrin residues varied depending on the type of tea. The EF of isomer 1R-3R-αS increased in black and dark tea samples (EF = 0.200-0.343) compared with the reference cypermethrin commercial mixture (EF = 0.116). In one oolong tea sample it was found that the relative abundance of some isomers was preferentially enhanced: 1R-3R-αS (EF = 0.260), 1S-3S-αR (EF = 0.263) and 1R-3S-αS/1S-3R-αR (the last elution peak, EF = 0.275). The relationship between EF and compound concentration was also analysed, showing that the variation in EFs of cypermethrin was concentration-dependent.CONCLUSION: These findings appear to be useful for assessing the species-specific risk of exposure to cypermethrin and cis-bifenthrin. Copyright
The soundness of steel pipes welds is primarily determined by the quality and penetration of the root pass. In order to ensure quality welds with full penetration, the gas tungsten arc welding (GTAW) ...process is widely used in industry. Pulsed current GTAW can significantly reduce total welding heat input, weld heat-affected zone (HAZ), residual stresses, and welding distortion, but the welding parameters are more complicated. Usually, the quality of manual GTA welding almost solely depends on the experience of individual welders, but the quality of automatic orbital welding is greatly influenced by proper selection and control of welding parameters to overcome the influences from gravity, arc force, surface tension, heat accumulation, joint preparation, and fit up precision, etc. Consequently, an automatic-welding system without feedback control may easily result in poor welding quality, especially in field welding when the joint preparation and fit up precision are far from ideal.
In this paper, an automatic pulsed GTAW system with fuzzy control technique was proposed by using a real-time root bead image feedback, and the width of root pass was used as control indication for full penetration. Bead width of the root pass was determined from CCD images signals using the edge detection technique. The rule of fuzzy controller is based on experiences acquired from welding of single-V grooved plates. Experiments show that the welding quality of steel pipes was very successfully by using this nonlinear, multivariable, on-line controlled pulsed GTAW process.
Pyrethroids are widely used in tea production, and pesticide residues in brewed tea are becoming a major issue. Thus, an appropriate control method of pyrethroid residues in tea samples has to be ...developed and used to reduce the potential health hazard from consumption of pyrethroids. A method is described here for the simultaneous determination of 16 pyrethroid residues in tea samples. The insecticides were extracted using acetone and then underwent cleanup through a florisil column. Analysis was performed by gas chromatography with ion trap mass spectrometry (GC-IT-MS) in MS-MS mode. Retention time and specific ions were used for identification. Recoveries at spiked levels (0.001–0.2 µg/g) for the 16 pyrethroids ranged from 71.3% to 106.3%, and the coefficient of variation was less than 17% in each case. The limits of detection were from 0.001 to 0.05 µg/g. The proposed method was successfully applied to determine pyrethroid residues in 25 brewed made tea samples. It was found that there were bifenthrin, cyfluthrin, lamda-cyhalothrin, cypermethrin, dicofol, fenpropathrin, fenvalerate, fluvalinate, and tetramethrin residues in different samples with levels ranging from 1.18–3071.29 µg/kg.
This study was performed to assess the photothermal response of highly focused laser energy using infrared thermal imaging instrument to detect and assess the actual temperature distribution during ...flash lamp pumped pulsed dye laser (FLPPDL) treatment for port wine stain (PWS) patients and avoiding its complications.
A retrospective review of 40 patients with PWS birthmark treated with FLPPDL (l = 585 nm, tp = 1500 ms, 7 mm spot) was conducted over a 2-year period. Subjects' ages ranged between 28 and 46 years (mean 29 years); there were 24 females and 16 males. Twenty patients received non-cooling laser treatment (NC-LT) using light dosages of 5-12 J/cm 2 . Another 20 patients received cryogen spray cooling laser treatment (CSC-LT) using light dosages of 5-12 J/cm 2 . A real-time infrared thermal imaging and the thermal wave equation were used for assessment. The results of temperature distributions related to the energy change were analyzed.
Proper temperature measurement using infrared thermal imaging instrument and thermal wave equation in non-cooled PWS patients showed that the energy density of pulsed dye laser (PDL) higher than 7 J/cm 2 can reach >44°C and result in burn injury. However, when energy densities beyond 10 J/cm 2 were administered, along with using CSC, thermal damage was could still be minimized without the risk of damage to the treated area.
Using infrared thermal imaging instrument and thermal wave equation, we can predict the skin temperature distribution in FLPPDL for PWS patients during the treatment. In conjunction with CSC, the complications can be minimized.
Corrosion behaviour and intergranular corrosion (IGC) sensitivity of 6061 aluminium alloy were investigated using electrochemical polarisation. A 10% tensile stretching was carried out on as-quenched ...6061 alloys to understand the effect of pre-deformation on precipitation during subsequent aging treatments. Grain boundary (GB) TEM micrographs were taken to correlate the relationship between the changes in microstructure and corrosion resistance. For artificially aged 6061 alloys, the introduction of the 10% pre-deformation reduces the corrosion rate, but is unable to change their IGC susceptible nature. Conversely, pre-deformation dramatically reduces the pitting depth and pit distribution of naturally aged 6061 alloys. Needle-like β″ precipitates were found homogeneously distributed in the matrix and the GB areas in the pre-deformed and naturally aged 6061-T3. It is suggested that strain-induced dislocations and misorientation sites cover the lack of vacancies around the as-quenched GBs, therefore promote homogeneous precipitation across the GBs which improves resistance against localised corrosion.
In this study, the effects of pre-deformation on mechanical properties and stress corrosion cracking behaviour of 7075 alloy was investigated with SSRT and electrochemical polarization. The 10% ...pre-deformation substantially improves the SCC resistance of the 7075 alloys. The strain induced dislocations act as diffusion shortcuts and result in enhanced precipitation and early appearance of GBPs in the naturally aged 7075-T3. For artificial aging, pre-deformation causes rapid over-aging as larger precipitates are found in both matrix and GBs of the 7075-T8. The substitution of Cu for Zn in the GBPs and the larger GBPs acting as hydrogen traps are possible explanations for the improved SCC resistance of 7075-T8. Further improvements in SCC resistance can be found in the RRA treated 7075 alloys, while a more ductile behaviour can be seen in the pre-deformed 7075 alloy. Additionally, results of electrochemical testing are in high correlation with the SSRT results.
In this study, a gas chromatography method for the multiresidue determination of 13 phenoxy acid herbicide residues (4-CPA, 4-CPP, phenoxy butyric acid, dicamba, MCPA, MCPP, MCPB, 2,4-D, 3,4-D, ...2,4,5-T, 2,4,5-TP, 2,4-DP, and 2,4-DB) in soybean was developed. After the removal of fat using n-hexane, the sample was extracted with acetonitrile-50 mM HCl (v/v 7:3), and then followed by liquid-liquid partition with n-hexane (saturated by acetonitrile). The soybean extract was further cleaned up by anion exchange column. Then the residues were derived with pentafluorobenzyl bromide and the resulting pentafluorobenzyl (PFB) esters were analyzed by a gas chromatograph equipped with an electron capture detector (ECD), quantified by the external standard method. Recoveries of spiked samples at two fortified levels (0.01 and 0.1 mg/kg) are all above 70%. And the relative standard deviation was less than 20%. It shows that the limits of determination (LOD) of this method (S/N≥3) can meet the requirement of maximum residue analysis in import/export inspection for soybean.
A method was developed to determine six pyrethroids (tau-fluvalinate, fenpropathrin, λ-cyhalothrin, cyfluthrin, α-cypermethrin and deltamethrin) in pork muscle by immunoaffinity column cleanup and ...gas chromatography-electron capture detection. Spiked pork muscle samples at 5, 20, 50 μg kg⁻¹ were extracted with petroleum spirit-diethyl ether (1:1, v/v). Fat was eliminated by liquid-liquid partition between acetonitrile and petroleum spirit. An immunoaffinity column (IAC) was used for further cleanup. The IAC column was prepared by coupling the polyclonal antibodies to the protein A sepharose gel and the resulting affinity gel columns were sufficiently stable for multiple reuse. Target compounds were adsorbed at pH 7.4 and after extensive washing, eluted with 3 mL methanol. Recoveries of the six pyrethroids were typically >70%. The detection limit was 2 μg kg⁻¹ for λ-cyhalothrin and α-cypermethrin and 5 μg kg⁻¹ for cyfluthrin, deltamethrin, fenpropathrin and tau-fluvalinate. Repeat analyses of pork muscle samples showed good repeatability. The method was applied to detect residues in meat samples.
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