Droplet digital PCR (ddPCR) for the detection and quantification of Ureaplasma spp.

BACKGROUND: Ureaplasma spp. are associated with various infectious diseases in females, but there is still limited evidence regarding whether they are related to nonspecific cervicitis. The aim of this study was to develop and evaluate a digital droplet PCR (ddPCR) assay for the detection and quantification of Ureaplasma spp. in cervical swabs. METHODS: A total of 267 non-specific cervicitis (NSC) patients and 195 asymptomatic females were included in this study. We produced standard curves for Ureaplasma spp. to evaluate the analytical performance of the ddPCR assay. Then, we detected and quantified the bacterial load of Ureaplasma spp. in cervical swabs. RESULTS: The prevalences of U. parvum were 37.8% (101/267) and 29.7% (58/195),  U. urealyticum were 9.0% (24/267) and 8.7% (17/195) in the NSC group and control group, respectively. In addition, the median copy number of U. parvum was 2.5 × 104 copies/ml (n = 101) in the NSC group and 9.2 × 103 copies/ml (n = 58) in the control group. The U. parvum load in the NSC group was significantly higher than that in the asymptomatic individuals (P < 0.001). whereas the median load of U. urealyticum was 8.4 × 103 copies/ml (n = 24) and 1.4 × 103 (n = 17) copies/ml in the two groups, respectively, , the difference was not statistically significant (P = 0.450). CONCLUSIONS: Our study is the first to develop a droplet digital PCR (ddPCR) method for the detection and quantification of Ureaplasma spp. in clinical samples, and the method has excellent analytical performance and a wide range of clinical application prospects.

Strategies for obstacle crossing in older adults with high and low risk of falling.

[Purpose] Tripping is a frequent cause of falls among aging adults. Appropriate limb movements while negotiating obstacles are critical to trip avoidance. The aim of our study was to investigate the mechanics of obstacle crossing in older adults at low or high risk of falling. [Subjects and Methods] Twenty community-dwelling adults aged ≥55 years, were evaluated with the Tinetti Balance and Gait scale and classified as being at high or low risk of falling. Between-group comparisons of kinematics were evaluated for obstacle heights of 10%, 20%, and 30% of leg length. [Results] The high-risk group demonstrated greater toe-obstacle clearance of the leading leg. Increasing obstacle height led to increased maximal toe-obstacle clearance, toe-obstacle distance, and shortened swing phase of the leading limb. Adaptation of clearance height was greater for the trailing leg. Individuals at high risk of falling demonstrated less symmetry between the leading and trailing legs and a narrower step width, features that increase the likelihood of tripping. [Conclusion] Kinematic parameters of obstacle clearance, including the symmetry index described in our study, could provide clinicians with a quick screening tool to identify patients at risk of falling and to evaluate outcomes of training programs.

Prognostic Value of Stem Cell Index-Related Characteristics in Primary Hepatocellular Carcinoma.

The objective of this study is to form a cancer stem cell index-based model to stratify HCC risk and predict survival. After screening the Tumor Genome Atlas (TCGA) of liver and normal liver tissue samples, we obtained differentially expressed genes (DEGs). We employed a weighted correlation network analysis (WGCNA) and differentially expressed genes were studied in HCC to find the modules most associated with cancer stem cells (mRNAsi). At the same time, gene ontology and Kyoto Genome Encyclopedia (KEGG) were used for functional annotation and combined with LASSO, univariate, and multivariate COX regression analyses, a prediction model of key module genes of cancer stem cells was developed. The model's clinical efficacy was measured using the C index, calibration curve, multiindex ROC curve, and clinical decision curve. WGCNA found that black modules were most correlated with tumour stem cell index. Seven genes (CSDC2, GNA14, LGI2, MMRN1, PDE2A, SELP, and STK32B) were filtered by univariate, LASSO, and multivariate Cox regression analyses to establish the primary HCC model. The survival analysis and ROC curve in the TCGA training and validation cohort showed good performance. The independent prognostic factor of primary HCC was risk score, according to univariate and multivariate Cox regression analyses. It is found that the stem cell index model of 7 genes could predict factors independently, indicating that signatures of the stem cell will play a significant role in liver cancer survival prediction and risk stratification.

Lithium and magnesium complexes by using pyridyl-pendanted unsymmetrical ß-diketiminates: syntheses and application as catalysts for the hydroboration of carbonyl compounds.

The push for environmentally benign and sustainable chemical processes has reinforced the demand to displace transition metals with cheap, nontoxic and naturally abundant metals. To fulfil this requirement, we endeavored to synthesize alkali- and alkaline earth-metal complexes and employ them as catalysts for organic transformations. Two lithium and one magnesium complexes, which are supported by pyridyl-pendanted unsymmetrical ß-diketiminates, have been synthesized and characterized. They are formulated as [Li(L1)]2 (1), [Li(L2)]2 (2) and [Mg(L2)2]·0.5C6H14 (3) (HL1 = N{-4-[(2,6-diisopropylphenylamino)pent-3-en-2-ylidene]-6-methyl}pyridin-2-amine and HL2 = N-{4-[(2,6-diisopropylphenyl)imino]pent-2-en-2-yl}pyridin-2-amine). Complex 1 features two inequivalent Li(I) sites. One Li(I) center exhibits tetrahedral geometry, while the other Li(I) ion adopts a triangular coordination sphere. The catalytic activities of 1-3 toward the hydroboration of aldehydes and ketones by pinacolborane (HBpin) were investigated. Both dinuclear lithium complexes and homoleptic magnesium compound were found to be highly efficient catalysts for the hydroboration of aldehydes and ketones, affording the corresponding borate esters in good yields within a very short time. Synthetic application of the complexes was demonstrated by the gram-scale reduction of ketones via a one-pot two step reaction with only 0.2 mol% loading of 2. Mechanistic details for the hydroboration were revealed by DFT calculations.

The role of a two-assay serological testing strategy for anti-HCV screening in low-prevalence populations.

HCV screening depends mainly on a one-assay anti-HCV testing strategy that is subject to an increased false-positive rate in low-prevalence populations. In this study, a two-assay anti-HCV testing strategy was applied to screen HCV infection in two groups, labelled group one (76,442 people) and group two (18,415 people), using Elecsys electrochemiluminescence (ECL) and an Architect chemiluminescent microparticle immunoassay (CMIA), respectively. Each anti-HCV-reactive serum was retested with the other assay. A recombinant immunoblot assay (RIBA) and HCV RNA testing were performed to confirm anti-HCV positivity or active HCV infection. In group one, 516 specimens were reactive in the ECL screening, of which CMIA retesting showed that 363 (70.3%) were anti-HCV reactive (327 positive, 30 indeterminate, 6 negative by RIBA; 191 HCV RNA positive), but 153 (29.7%) were not anti-HCV reactive (4 positive, 29 indeterminate, 120 negative by RIBA; none HCV RNA positive). The two-assay strategy significantly improved the positive predictive value (PPV, 64.1% & 90.1%, P < 0.05). In group two, 87 serum specimens were reactive according to CMIA screening. ECL showed that 56 (70.3%) were anti-HCV reactive (47 positive, 8 indeterminate, 1 negative by RIBA; 29 HCV RNA positive) and 31 (29.7%) were anti-HCV non-reactive (25 negative, 5 indeterminate, 1 positive by RIBA; none HCV RNA positive). Again, the PPV was significantly increased (55.2% & 83.9%, P < 0.05). Compared with a one-assay testing strategy, the two-assay testing strategy may significantly reduce false positives in anti-HCV testing and identify inactive HCV infection in low-seroprevalence populations.

Postanesthesia alternation of lower limb contractures in children with spastic cerebral palsy.

The aim of this study was to clarify the effects of general anesthesia (GA) on joint range of motion (ROM) in children with spastic cerebral palsy (SCP). Eighty-four SCP cases (mean age 8.4 years) admitted for first corrective surgery were retrospectively reviewed. Lower limb ROM were measured 1 day before operation and immediately after GA. Contracture of hip, knee, and ankle joints decreased significantly after GA, with + 11.1° (39.5%) for the hip abduction angle, -3.7° (18.0%) for the Thomas test, -15.0° (19.1%) for the popliteal angle, + 6.6° (39.8%) and 7.0° (109%) for ankle dorsiflexion with knee flexion and extension, respectively (all P < 0.001). These changes were correlated positively to pre-GA contracture and body weight, negatively to age, but independent of preoperative functional level, geographic classification of SCP, or modified Ashworth scale. On the basis of these findings, routine post-GA reassessments of joint ROM before corrective surgeries were recommended for pediatric SCP cases.

Structural dynamics of nitrosylruthenium isomeric complexes studied with steady-state and transient pump-probe infrared spectroscopies.

The characteristic nitrosyl stretching (NO) in the region of 1800-1900cm(-1) was used to study the geometric and ligand effect on two nitrosylruthenium complexes, namely [Ru(OAc)(2QN)2NO] (QN=2-chloro-8-quinolinol (H2cqn) or QN=2-methyl-8-quinolinol (H2mqn)). The NO stretching frequency (νNO) was found in the following order: νcis-1 (2cqn)>νcis-2 (2cqn)>νcis-1 (2mqn)>νtrans (2mqn). The results exhibited a spectral sensitivity of the NO mode to both charge distribution and ligand arrangement, which was supported by ab initio computations and natural bond orbital (NBO) analyses. Further, the vibrational population of the vibrationally excited NO stretching mode was found to relax on the order of 7-10ps, showing less than 30% variation from one isomer to another, which were explained on the basis of NO local structures and solute-solvent interactions in these isomeric nitrosylruthenium complexes.

Differentiating Two Nitrosylruthenium Isomeric Complexes by Steady-State and Ultrafast Infrared Spectroscopies.

The [Ru(II)-NO+] group affects the structure and chemical reactivity of nitrosylruthenium(II) complexes. A characteristic infrared absorption band due to the nitrosyl (NO) stretching motion is shown in the frequency region 1800-1900 cm-1. In this work, linear infrared (IR) and nonlinear IR methods, including pump-probe and two-dimensional (2D) IR, were utilized to study the structures and dynamics of two isomeric nitrosylruthenium complexes [Ru(OAc)(2mqn)2NO] (H2mqn = 2-methyl-8-quinolinol) in cis and trans isomeric configurations in a weak polar solvent (CDCl3). Using the NO stretching mode as a vibrational probe, information about local structural dynamics of the Ru complex as well as solvent fluctuation dynamics was obtained. In particular, a "structured" solvent environment is believed to form in the vicinity of the NO group in the case of the cis isomer with the aid of a neighboring OAc ligand, which is the reason for more efficient vibrational relaxation but more inhomogeneously distributed solvent and thus associated slower spectral diffusion. Our results also suggest a more anharmonic potential surface for the NO stretching mode in the less stable trans isomer.

Impact of foot progression angle on the distribution of plantar pressure in normal children.

BACKGROUND: Plantar pressure distribution during walking is affected by several gait factors, most especially the foot progression angle which has been studied in children with neuromuscular diseases. However, this relationship in normal children has only been reported in limited studies. The purpose of this study is to clarify the correlation between foot progression angle and plantar pressure distribution in normal children, as well as the impacts of age and sex on this correlation. METHODS: This study retrospectively reviewed dynamic pedobarographic data that were included in the gait laboratory database of our institution. In total, 77 normally developed children aged 5-16 years who were treated between 2004 and 2009 were included. Each child's footprint was divided into 5 segments: lateral forefoot, medial forefoot, lateral midfoot, medial midfoot, and heel. The percentages of impulse exerted at the medial foot, forefoot, midfoot, and heel were calculated. FINDINGS: The average foot progression angle was 5.03° toe-out. Most of the total impulse was exerted on the forefoot (52.0%). Toe-out gait was positively correlated with high medial (r = 0.274; P < 0.001) and forefoot impulses (r = 0.158; P = 0.012) but negatively correlated with midfoot impulse (r = -0.273; P<0.001). The moderating effects of age and sex on these correlations were insignificant. INTERPRETATION: Foot progression angle demonstrates significant impact on the distribution of foot pressure, regardless of age or sex. Foot progression angle should be taken into consideration when conducting pedobarographic examinations and balancing plantar pressure as part of the treatment of various foot pathologies.