Three-dimensional bioprinting of artificial ovaries by an extrusion-based method using gelatin-methacryloyl bioink.

PURPOSE: The aim of this study was to design and fabricate a three-dimensional (3D) printed artificial ovary. METHODS: We first compared the printability of gelatin-methacryloyl (GelMA), alginate and GelMA-alginate bioinks, of which GelMA was selected for further investigation. The swelling properties, degradation kinetics and shape fidelity of GelMA scaffolds were characterized by equilibrium swelling/lyophilization, collagenase processing and micro-computed tomography evaluation. Commercial ovarian tumor cell lines (COV434, KGN, ID8) and primary culture ovarian somatic cells were utilized to perform cell-laden 3D printing, and the results were evaluated by live/dead assays and TUNEL detection. Murine ovarian follicles were seeded in the ovarian scaffold and their diameters were recorded every day. Finally, in vitro maturation was performed, and the ovulated oocytes were collected and observed. RESULTS: Our results indicated that GelMA was suitable for 3D printing fabrication. Its scaffolds performed well in terms of hygroscopicity, degradation kinetics and shape fidelity. The viability of ovarian somatic cells was lower than that of commercial cell lines, suggesting that extrusion-based 3D culture fabrication is not suitable for primary ovarian cells. Nevertheless, the GelMA-based 3D printing system provided an appropriate microenvironment for ovarian follicles, which successfully grew and ovulated in the scaffolds. Metaphase II oocytes were also observed after in vitro maturation. CONCLUSIONS: The GelMA-based 3D printing culture system is a viable alternative option for follicular growth, development and transfer. Accordingly, it shows promise for clinical application in the treatment of female endocrine and reproductive conditions.

[Bacterial community diversity in Dermatophagoides farinae using high-throughput sequencing].

OBJECTIVE: To investigate the bacterial community diversity in Dermatophagoides farinae. METHODS: Laboratory-cultured D. farinae was collected, and the composition of microbial communities was determined by sequence analyses of the V4 region in the bacterial 16S ribosomal RNA (16S rRNA) gene on an Illumina PE250 high-throughput sequencing platform. Following quality control and filtering of the raw sequence files, valid reads were obtained and subjected to operational taxonomic units (OTU) clustering and analysis of the composition of microbial communities and alpha diversity index using the Usearch software, Silva database, and Mothur software. RESULTS: A total of 187 616 valid reads were obtained, and 469 OTUs were clustered based on a sequence similarity of more than 97%. OTU annotation showed that the bacteria in D. farinae belonged to 26 phyla, 43 classes, 100 orders, 167 families and 284 genera. The bacteria in D. farinae were mainly annotated to five phyla of Proteobacteria, Firmicutes, Bacteroidota, Actinobacteriota, and Acidobacteriota, with Proteobacteria as the dominant phylum, and mainly annotated to five dominant genera of Ralstonia, norank-f-Mitochondria, Staphylococcus and Sphingomonas, with Wolbachia identified in the non-dominant genus. CONCLUSIONS: A high diversity is identified in the composition of the bacterial community in D. farinae, and there are differences in bacterial community diversity and abundance among D. farinae.

[Effects of copper and cadmium ions on protective enzyme activity in Oncomelania hupensis].

OBJECTIVE: To evaluate the effects of Cu2+ and Cd2+ at different concentrations on superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) activity in Oncomelania hupensis. METHODS: Cu2+- and Cd2+-containing solutions were prepared at 7 concentrations, and O. hupensis snails were exposed to the solutions for 24 h, of 15 snails in each concentration. Then, the snail body was collected following removal of the snail shell and homogenated, and the SOD, CAT and POS activities were detected in the supernatants. RESULTS: With the increase of the Cu2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline-rise-decline tendency, while the POD activity showed a tendency towards rise followed by decline. With the increase of the Cd2+ concentration, the SOD activity appeared a rise followed by a reduction in O. hupensis snails, and the CTA activity appeared a decline- rise- decline tendency, while the POD activity showed a decline-rise-decline tendency. CONCLUSIONS: Exposure to Cu2+ and Cd2+ at high concentrations results in a decline in the activity of SOD, CAT and POD in O. hupensis at the same time.

Experimental study of a compact piezoelectric micro-perforated panel absorber with adjustable acoustic property.

This work aims to investigate the acoustic characteristics of a piezoelectric micro-perforated panel (MPP) absorber, which is made of a perforated polyvinylidene fluoride (PVDF) film with a backed airgap of 2 cm, as a combination of an active component and passive absorber. In addition to its inherent passive dissipation, as the PVDF-MPP was driven with proper voltages and oscillation frequencies, sound absorption coefficients of the absorber adjacent to the driving frequencies were significantly increased. Compared with mostly previous reported hybrid passive-active absorbers, this one is more compact, and its acoustic property is adjustable, it may provide an approach to achieve intelligent noise control.

Effect of irrigation on surface roughness and fatigue resistance of controlled memory wire nickel-titanium instruments.

AIM: To investigate the effect of irrigation on the surface roughness and fatigue resistance of HyFlex and M3 controlled memory (CM) wire nickel-titanium instruments. METHODOLOGY: Two new files of each brand were analysed by atomic force microscopy (AFM). Then, the instruments were dynamically immersed in either 5.25% sodium hypochlorite (NaOCl) or 17% ethylene diamine tetraacetic acid (EDTA) solution for 10 min, followed by AFM analysis. The roughness average (Ra) and root mean square (RMS) values were analysed statistically using an independent sample t-test. Then, 36 files of each brand were randomly assigned to three groups (n = 12). Group 1 (the control group) was composed of new instruments. Groups 2 and 3 were dynamically immersed in 5.25% NaOCl and 17% EDTA solutions for 10 min, respectively. The number of rotations to failure for various groups was analysed using the one-way analysis of variance software. RESULTS: For M3 files, the Ra and RMS values significantly increased (P < 0.05) after the immersion. For the HyFlex file, the Ra and RMS values significantly increased (P < 0.05) only in EDTA, but not (P > 0.05) NaOCl. The resistance to cyclic fatigue of both HyFlex and M3 files did not significantly decrease (P > 0.05) by immersing in 5.25% NaOCl and 17% EDTA solutions. CONCLUSIONS: Except the HyFlex files immersed in NaOCl, the surface roughness of other files exposed to irrigants increased. However, a change in the surface tomography of CM wire instruments caused by contact with irrigants for 10 min did not trigger a decrease in cyclic fatigue resistance.

Isolation and characterization of 19 highly polymorphic microsatellite markers in the devil stinger, Inimicus japonicus (Synanceiidae).

Inimicus japonicus, the devil stinger, has an extensive distribution along the coast of China, Japan and the Korean Peninsula. Nineteen highly polymorphic microsatellite markers were isolated and characterized in I. japonicus. Twenty-eight individuals from a wild population were tested for polymorphism using this set of polymorphic microsatellite markers. The number of alleles per locus ranged from 4 to 14. The ranges of observed and expected heterozygosity were 0.500-0.892 and 0.521-0.910, respectively. Significant deviations from Hardy-Weinberg equilibrium were detected at two loci. To the best of our knowledge, these were the first microsatellite loci characterized from the Synanceiidae; they can be used for estimating genetic diversity, population structure studies, parentage analysis, genetic linkage map construction, germplasm classification and identification, gene identification, quantitative trait loci mapping, and marker-assisted selection in breeding of I. japonicus and other species of this family.

Modeling the rovibrationally excited C2H4OH radicals from the photodissociation of 2-bromoethanol at 193 nm.

This study photolytically generates, from 2-bromoethanol photodissociation, the 2-hydroxyethyl radical intermediate of the OH + ethene reaction and measures the velocity distribution of the stable radicals. We introduce an impulsive model to characterize the partitioning of internal energy in the C(2)H(4)OH fragment. It accounts for zero-point and thermal vibrational motion to determine the vibrational energy distribution of the nascent C(2)H(4)OH radicals and the distribution of total angular momentum, J, as a function of the total recoil kinetic energy imparted in the photodissociation. We render this system useful for the study of the subsequent dissociation of the 2-hydroxyethyl radical to the possible asymptotic channels of the OH + ethene reaction. The competition between these channels depends on the internal energy and the J distribution of the radicals. First, we use velocity map imaging to separately resolve the C(2)H(4)OH + Br((2)P(3/2)) and C(2)H(4)OH + Br((2)P(1/2)) photodissociation channels, allowing us to account for the 10.54 kcal/mol partitioned to the Br((2)P(1/2)) cofragment. We determine an improved resonance enhanced multiphoton ionization (REMPI) line strength for the Br transitions at 233.681 nm (5p (4)P(1/2) <-- 4p (2)P(3/2)) and 234.021 nm (5p (2)S(1/2) <-- 4p (2)P(1/2)) and obtain a spin-orbit branching ratio for Br((2)P(1/2)):Br((2)P(3/2)) of 0.26 +/- 0.03:1. Energy and momentum conservation give the distribution of total internal energy, rotational and vibrational, in the C(2)H(4)OH radicals. Then, using 10.5 eV photoionization, we measure the velocity distribution of the radicals that are stable to subsequent dissociation. The onset of dissociation occurs at internal energies much higher than those predicted by theoretical methods and reflects the significant amount of rotational energy imparted to the C(2)H(4)OH photofragment. Instead of estimating the mean rotational energy with an impulsive model from the equilibrium geometry of 2-bromoethanol, our model explicitly includes weighting over geometries across the quantum wave function with zero, one, and two quanta in the harmonic mode that most strongly alters the exit impact parameter. The model gives a nearly perfect prediction of the measured velocity distribution of stable radicals near the dissociation onset using a G4 prediction of the C-Br bond energy and the dissociation barrier for the OH + ethene channel calculated by Senosiain et al. (J. Phys. Chem. A 2006, 110, 6960). The model also indicates that the excited state dissociation proceeds primarily from a conformer of 2-bromoethanol that is trans across the C-C bond. We discuss the possible extensions of our model and the effect of the radical intermediate's J-distribution on the branching between the OH + ethene product channels.

Apocynin improves outcome in experimental stroke with a narrow dose range.

Inflammation following ischemic stroke is known to contribute to injury. NADPH oxidase (NOX) is a major enzyme system originally studied in immune cells that leads to superoxide (O.*) generation. Apocynin is a NOX inhibitor that has been studied as a potential treatment in experimental stroke. Here we explored the effect of different doses of apocynin in a mouse model of 2 h transient middle cerebral artery occlusion (tMCAO) followed by 22 h reperfusion. Apocynin, given i.v. at a dose of 2.5 mg/kg 30 min before reperfusion, improved neurological function (P<0.01), reduced infarct volume (P<0.05), and reduced the incidence of cerebral hemorrhage (P<0.05), but not at higher doses of 3.75 and 5 mg/kg, where it actually increased brain hemorrhage. Apocynin also tended to reduce mortality at the lower dose, but not at higher doses. Using hydroethine fluorescence to delineate O.* in the brain, neurons and some microglia/macrophages, but not vascular endothelial cells were found to contain O.*. Apocynin at protective doses markedly prevented ischemia-induced increases in O.*. Our data suggested that apocynin can protect against experimental stroke, but with a narrow therapeutic window.

An experimental and quasiclassical trajectory study of the rovibrationally state-selected reactions: HD+(v=0-15,j=1)+He-->HeH+(HeD+)+D(H).

The absolute integral cross sections for the formation of HeH+ and HeD+ from the collisions of HD+(v,j=1)+He have been examined over a broad range of vibrational energy levels v=0-13 at the center-of-mass collision energies (ET) of 0.6 and 1.4 eV using the vacuum ultraviolet (VUV) pulsed field ionization photoelectron secondary ion coincidence method. The ET dependencies of the integral cross sections for products HeH+ and HeD+ from HD+(v=0-4)+He collisions in the ET range of 0-3 eV have also been measured using the VUV photoionization guided ion beam mass spectrometric technique, in which vibrationally selected HD+(v) reactant ions were prepared via excitation of selected autoionization resonances of HD. At low total energies, a pronounced isotope effect is observed in absolute integral cross sections for the HeH++D and HeD++H channels with significant favoring of the deuteron transfer channel. As v is increased in the range of v=0-9, the integral cross sections of the HeH++D channel are found to approach those of HeD++H. The observed velocity distributions of products HeD+ and HeH+ are consistent with an impulsive or spectator-stripping mechanism. Detailed quasiclassical trajectory (QCT) calculations are also presented for HD+(v,j=1)+He collisions at the same energies of the experiment. The QCT calculations were performed on the most accurate ab initio potential energy surface available. If the zero-point energy of the reaction products is taken into account, the QCT cross sections for products HeH+ and HeD+ from HD+(v)+He are found to be significantly lower than the experimental results at ET values near the reaction thresholds. The agreement between the experimental and QCT cross sections improves with translational energy. Except for prethreshold reactivity, QCT calculations ignoring the zero-point energy in the products are generally in good agreement with experimental absolute cross sections. The experimental HeH+/HeD+ branching ratios for the HD+(v=0-9)+He collisions are generally consistent with QCT predictions. The observed isotope effects can be rationalized on the basis of differences in thermochemical thresholds and angular momentum conservation constraints.

The study of state-selected ion-molecule reactions using the vacuum ultraviolet pulsed field ionization-photoion technique.

This paper presents the methodology to generate beams of ions in single quantum states for bimolecular ion-molecule reaction dynamics studies using pulsed field ionization (PFI) of atoms or molecules in high-n Rydberg states produced by vacuum ultraviolet (VUV) synchrotron or laser photoexcitation. Employing the pseudocontinuum high-resolution VUV synchrotron radiation at the Advanced Light Source as the photoionization source, PFI photoions (PFI-PIs) in selected rovibrational states have been generated for ion-molecule reaction studies using a fast-ion gate to pass the PFI-PIs at a fixed delay with respect to the detection of the PFI photoelectrons (PFI-PEs). The fast ion gate provided by a novel interleaved comb wire gate lens is the key for achieving the optimal signal-to-noise ratio in state-selected ion-molecule collision studies using the VUV synchrotron based PFI-PE secondary ion coincidence (PFI-PESICO) method. The most recent development of the VUV laser PFI-PI scheme for state-selected ion-molecule collision studies is also described. Absolute integral cross sections for state-selected H2+ ions ranging from v+ = 0 to 17 in collisions with Ar, Ne, and He at controlled translational energies have been obtained by employing the VUV synchrotron based PFI-PESICO scheme. The comparison between PFI-PESICO cross sections for the H2+(HD+)+Ne and H2+(HD+)+He proton-transfer reactions and theoretical cross sections based on quasiclassical trajectory (QCT) calculations and three-dimensional quantum scattering calculations performed on the most recently available ab initio potential energy surfaces is highlighted. In both reaction systems, quantum scattering resonances enhance the integral cross sections significantly above QCT predictions at low translational and vibrational energies. At higher energies, the agreement between experiment and quasiclassical theory is very good. The profile and magnitude of the kinetic energy dependence of the absolute integral cross sections for the H2+(v+ = 0-2,N+ = 1)+He proton-transfer reaction unambiguously show that the inclusion of Coriolis coupling is important in quantum dynamics scattering calculations of ion-molecule collisions.

Direct identification of propargyl radical in combustion flames by vacuum ultraviolet photoionization mass spectrometry.

We have developed an effusive laser photodissociation radical source, aiming for the production of vibrationally relaxed radicals. Employing this radical source, we have measured the vacuum ultraviolet (VUV) photoionization efficiency (PIE) spectrum of the propargyl radical (C(3)H(3)) formed by the 193 nm excimer laser photodissociation of propargyl chloride in the energy range of 8.5-9.9 eV using high-resolution (energy bandwidth = 1 meV) multibunch synchrotron radiation. The VUV-PIE spectrum of C(3)H(3) thus obtained is found to exhibit pronounced autoionization features, which are tentatively assigned as members of two vibrational progressions of C(3)H(3) in excited autoionizing Rydberg states. The ionization energy (IE = 8.674 +/- 0.001 eV) of C(3)H(3) determined by a small steplike feature resolved at the photoionization onset of the VUV-PIE spectrum is in excellent agreement with the IE value reported in a previous pulsed field ionization-photoelectron study. We have also calculated the Franck-Condon factors (FCFs) for the photoionization transitions C(3)H(3) (+)(X;nu(i),i = 1-12)<--C(3)H(3)(X). The comparison between the pattern of FCFs and the autoionization peaks resolved in the VUV-PIE spectrum of C(3)H(3) points to the conclusion that the resonance-enhanced autoionization mechanism is most likely responsible for the observation of pronounced autoionization features. We also present here the VUV-PIE spectra for the mass 39 ions observed in the VUV synchrotron-based photoionization mass spectrometric sampling of several premixed flames. The excellent agreement of the IE value and the pattern of autoionizing features of the VUV-PIE spectra observed in the photodissociation and flames studies has provided an unambiguous identification of the propargyl radical as an important intermediate in the premixed combustion flames. The discrepancy found between the PIE spectra obtained in flames and photodissociation at energies above the IE(C(3)H(3)) suggests that the PIE spectra obtained in flames might have contributions from the photoionization of vibrationally excited C(3)H(3) and/or the dissociative photoionization processes involving larger hydrocarbon species formed in flames.

A time-dependent wave-packet quantum scattering study of the reaction H2+(v = 0-2,4,6;j = 1) + He--> HeH+ + H.

The quantum scattering dynamics calculation was carried out for the titled reaction in the collision energy range of 0.0-2.4 eV with reactant H(2) (+) in the rotational state j = 1 and vibrational states v = 0-2, 4, and 6. The present time-dependent wave-packet calculation takes into account the Coriolis coupling (CC) and uses the accurate ab initio potential-energy surface of Palmieri et al. [Mol. Phys. 98, 1835 (2000)]. The importance of including the CC quantum scattering calculation has been revealed by the comparison between the CC calculation and the previous coupled state (CS) calculation. The CC total cross sections for the v = 2, 4, and 6 states show collision energy-dependent behaviors different from those based on the CS calculation. Furthermore, the collision energy dependence of the total cross sections obtained in the present CC calculation only exhibits minor oscillations, indicating that the chance is slim for reactive resonances in total cross sections to survive through the partial-wave averaging. The magnitude and profile of the CC total cross sections for v = 0-2 in the collision energy range of 0.0-2.5 eV are found to be consistent with experimental cross sections obtained recently by Tang et al. [J. Chem. Phys. 122, 164301 (2005)] after taking into account the experimental uncertainties.

A pulsed-field ionization photoelectron secondary ion coincidence study of the H2+ (X,upsilon+=0-15,N+=1)+He proton transfer reaction.

The endothermic proton transfer reaction, H2+(upsilon+)+He-->HeH+ + H(DeltaE=0.806 eV), is investigated over a broad range of reactant vibrational levels using high-resolution vacuum ultraviolet to prepare reactant ions either through excitation of autoionization resonances, or using the pulsed-field ionization-photoelectron-secondary ion coincidence (PFI-PESICO) approach. In the former case, the translational energy dependence of the integral reaction cross sections are measured for upsilon+=0-3 with high signal-to-noise using the guided-ion beam technique. PFI-PESICO cross sections are reported for upsilon+=1-15 and upsilon+=0-12 at center-of-mass collision energies of 0.6 and 3.1 eV, respectively. All ion reactant states selected by the PFI-PESICO scheme are in the N+=1 rotational level. The experimental cross sections are complemented with quasiclassical trajectory (QCT) calculations performed on the ab initio potential energy surface provided by Palmieri et al. [Mol. Phys. 98, 1839 (2000)]. The QCT cross sections are significantly lower than the experimental results near threshold, consistent with important contributions due to resonances observed in quantum scattering studies. At total energies above 2 eV, the QCT calculations are in excellent agreement with the present results. PFI-PESICO time-of-flight (TOF) measurements are also reported for upsilon+=3 and 4 at a collision energy of 0.6 eV. The velocity inverted TOF spectra are consistent with the prevalence of a spectator-stripping mechanism.

Multiple pleural nodules without effusion--a rare presentation of tuberculous pleurisy.

We report a rare case of tuberculous pleurisy presenting with multiple pleural nodules without associated effusion or parenchymal lung lesions. A 62-year-old man had multiple discrete pleural nodules in the right hemithorax on chest radiography without any clinical symptoms. Thoracoscopic biopsy of the pleural nodules revealed a caseous granuloma with acid-fast bacilli. The patient received antituberculous therapy, with resolution of tuberculomas on chest film within 2 months. To our knowledge, only two similar cases have been previously reported in the English literature, and our observation should lead to broadening of the spectrum of the differential diagnosis of multiple pleural nodules.