Mechanism of YAP1 in the senescence and degeneration of endplate chondrocytes induced by intermittent cyclic mechanical tension

BACKGROUND

This study aimed to investigate the potential mechanism of YAP1 in the senescence and degeneration of endplate chondrocytes induced by intermittent cyclic mechanical tension (ICMT).

METHODS

According to the Pfirrmann grade evaluation classification, 30 human endplate cartilage tissues were divided into the lumbar vertebra fracture (LVF) group and lumbar disc herniation (LDH) group. Then, quantitative reverse transcription polymerase chain reaction, western blot, flow cytometry, hematoxylin-eosin staining, and senescence-associated β-galactosidase staining were performed. The difference in extracellular matrix expression between LVF and LDH endplate cartilage was detected. Second, the effect of ICMT on endplate chondrocytes degeneration was observed. Finally, the key regulatory role of YAP1 in ICMT-induced endplate cartilage degeneration was further verified.

RESULTS

In degraded human endplate cartilage and tension-induced degraded endplate chondrocytes, the expression of YAP1, COL-2A, and Sox9 was decreased. Conversely, the expression of p53 and p21 was increased. By regulating YAP1 in vivo and in vitro, we can achieve alleviation of ICMT-induced senescence of endplate chondrocytes and effective treatment of disc degeneration.

CONCLUSIONS

ICMT could induce senescence and degeneration of endplate chondrocytes, and ICMT-induced senescence and degeneration of endplate chondrocytes could be alleviated by regulating YAP1 expression.

Phylogeography and evolutionary dynamics analysis of porcine delta-coronavirus with host expansion to humans

From 2003 onwards, three pandemics have been caused by coronaviruses: severe acute respiratory syndrome coronavirus (SARS-CoV); middle east respiratory syndrome coronavirus (MERS-CoV); and, most recently, SARS-CoV-2. Notably, all three were transmitted from animals to humans. This would suggest that animals are potential sources of epidemics for humans. The emerging porcine delta-coronavirus was reported to infect children. This is a red flag that marks the ability of PDCoV to break barriers of cross-species transmission to humans. Therefore, we conducted molecular genetic analysis of global clade PDCoV to characterize spatio-temporal patterns of viral diffusion and genetic diversity. PDCoV was classified into three major lineages, according to distribution and phylogenetic analysis of PDCoV. It can be inferred based on the analysis results of the currently known PDCoV strains that PDCoV might originate in Asia. We also selected six special spike amino acid sequences to align and analyze to find seven significant mutation sites. The accumulation of these mutations may enhance dynamic movements, accelerating spike protein membrane fusion events and transmission. Altogether, our study offers a novel insight into the diversification, evolution, and interspecies transmission and origin of PDCoV and emphasizes the need to study the zoonotic potential of the PDCoV and comprehensive surveillance and enhanced biosecurity precautions for PDCoV. This article is protected by copyright. All rights reserved.

[Mineral nitrogen accumulation and its spatial distribution in soils in dense planting dwarf rootstock apple orchard on the Weibei dry plateau, Northwest China]

With the rapid development of dense apple tree plantings with the dwarf rootstock cultivation method, determining accumulation and distribution characteristics of soil mineral nitrogen in densely planted orchards with dwarf rootstock is important to enable scientific fertilization of apple orchards. We investigated densely planted apple orchards with dwarf rootstocks and different plant ages (6 a, 9 a, and 12 a). We collected soil samples under trees, between trees, between rows, and at the midpoints between the trees and rows, and examined the accumulation and distribution characteristics of nitrate, ammonium, and mineral nitrogen. The cumulative amount of nitrate in the 0-300 cm soil layer increased with plant age. The difference between orchards with different plant ages was significant and showed the trend 6 a<9 a<12 a. The cumulative amount of nitrate increased from 1729 kg·hm^-2 to 3771 kg·hm^-2 with increasing plant age. The ammonium content was low for orchards of all plant ages and had little effect on the accumulation and spatial distribution of mineral nitrogen. There were two accumulation peaks of nitrate nitrogen in the vertical direction. The depth of soil layer where the second accumulation peak was located decreased from 180 cm to 220 cm with increasing plant age. In the horizontal direction, soil nitrate nitrogen content between rows increased from 27 mg·kg^-1 to 138 mg·kg^-1 with increasing plant age, representing a more than 400% increase. The difference between orchards with different plant ages was significant. In summary, excessive usage of nitrogen fertilizer and serious leaching of nitrate were problematic in all orchards with different ages. Less nitrogen fertilizer should be applied, and anti-seepage measures should be used at the fertilization location to prevent the leaching of nitrate to deep layers.

Clinicoradiological features associated with epidermal growth factor receptor exon 19 and 21 mutation in lung adenocarcinoma

AIM

To retrospectively identify clinicopathological and radiological characteristics that could be independent predictors of epidermal growth factor receptor (EGFR) exon 19 and 21 mutation in surgically resected lung adenocarcinomas in a cohort of Asian patients.

MATERIALS AND METHODS

Demographics, histopathology data, and preoperative chest computed tomography (CT) images were evaluated retrospectively in 471 surgically resected lung adenocarcinomas. A total of 24 CT descriptors were assessed. Univariate analyses and multivariate logistic regression analyses were performed to identify independent predicted factors of harbouring EGFR mutations.

RESULTS

EGFR mutations were existed in 252 (53.5%) of 471 patients, and associated with 11 clinicoradiological features. For the model with both clinical and radiological features, the independent predictors of harbouring EGFR mutation were small maximum diameter (≤3.9 cm), non-smokers, micropapillary pattern, pleural retraction, vascular convergence, and absence of solid pattern. The area under the receiver operating characteristic (ROC) curve (AUC) was 0.784. Multivariable logistic regression analysis indicated that non-smokers, vascular convergence, and absence of solid pattern were important independent predictors of EGFR exon 19 mutation, while non-smokers and vascular convergence were independent predictors of EGFR exon 21 mutation. The AUCs were 0.807 and 0.794, respectively. A lepidic growth pattern appeared more frequently in exon 21 mutant tumours than in exon 19 mutant group (p<0.001).

CONCLUSION

CT imaging features of lung adenocarcinomas in combination with clinical variables could be used to prognosticate EGFR mutation status. The separate analysis of EGFR exon 19 or 21 mutation could further improve diagnostic performance.

[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.

[Efficacy of subgingival glycine air polishing on patients with early peri-implant diseases]

Objective: To compare the clinical efficacies of subgingival glycine air polishing and ultrasonic scaling combined with 0.12% chlorhexidine rinsing on patients with early peri-implant diseases (peri-implant mucositis and early peri-implantitis). Methods: Twenty-two systemically healthy patients with totally 42 implants and early peri-implant diseases, were recruited in this study. The patients were randomly divided into the test group and the control group. Patients in the test group were treated with subgingival glycine air polishing and patients in the control group were treated with ultrasonic scalers combined with 0.12% chlorhexidine rinsing. Periodontal parameters such as probing depth, bleeding index, plaque index and clinical attachment loss, at baseline and 2 months after treatment, respectively, were collected and compared between the test and control groups. Results: For the natural teeth, the parameters of probing depth, bleeding index, plaque index and attachment loss in the two groups were significantly improved after treatments (medians were 0.48 mm vs 0.22 mm, 1.00 vs-0.13, 0.38 vs 0.50, 0.48 mm vs 0.22 mm, respectively for test and control group). There was no statistical difference of median between the two groups after treatment except for that of the attachment loss (medians, 0.48 mm vs 0.22 mm, P=0.034). For the implants, differences of parameters in the two groups at baseline were insignificant. After treatments, the probing depths significantly decreased by 0.67 mm and 0.33 mm in the test group and the control group, respectively. The inter-group differences, however, were insignificant. Significant difference of the bleeding index after treatment was found in the test group (P=0.019), but not in the control group. No adverse reactions were found on patients in the two groups after treatments. Conclusions: Efficacy of subgingival glycine air polishing and ultrasonic scaling combined with 0.12% chlorhexidine rinsing is competitive on patients with early peri-implant diseases. However, the former treatment may be more effective oncontrolling the early peri-implant inflammation.

Chiral-aminoquinoline-based fluorescent pH probe with large stokes shift for bioimaging

The aminoquinoline derivatives, (R)- and (S)-2-phenyl-2-(quinolin-6-ylamino)ethan-1-ol (R-PEO and S-PEO), were synthesized by a tandem one-pot three-step CN coupling method where Smiles rearrangement was the key procedure. The selected compound R-PEO showed a significant fluorescence enhancement with a turn-on ratio over 98-fold and enabled the real time determination of proton concentration in acidic solution. The fluorescence intensity of R-PEO exhibited strong pH-dependent performance with a large Stokes shift (115nm) and responded linearly to minor pH change within the range of 3.8-6.0. With the help of ¹H NMR spectrum, we also confirmed the protonation of the quinoline unit should be the proposed reaction. Compared with the conjugated acid of N-hexylquinolin-6-amine (NQA), the conjugated acid of R-PEO shows significant planar intramolecular charge transfer (PICT) character. Furthermore, biological imaging proved that R-PEO probe can be used to monitor the pH change of S. cerevisiae in vivo.

[Characteristics of soil moisture in artificial impermeable layers]

For the problem of low water and fertilizer use efficiency caused by nitrate nitrogen lea- ching into deep soil layer and soil desiccation in dryland apple orchard, characteristics of soil moisture were investigated by means of hand tamping in order to find a new approach in improving the water and fertilizer use efficiency in the apple orchard. Two artificial impermeable layers of red clay and dark loessial soil were built in soil, with a thickness of 3 or 5 cm. Results showed that artificial impermeable layers with the two different thicknesses were effective in reducing or blocking water infiltration into soil and had higher seepage controlling efficiency. Seepage controlling efficiency for the red clay impermeable layer was better than that for the dark loessial soil impermeable layer. Among all the treatments, the red clay impermeable layer of 5 cm thickness had the highest bulk density, the lowest initial infiltration rate (0.033 mm · min(-1)) and stable infiltration rate (0.018 mm · min(-1)) among all treatments. After dry-wet alternation in summer and freezing-thawing cycle in winter, its physiochemical properties changed little. Increase in years did not affect stable infiltration rate of soil water. The red clay impermeable layer of 5 cm thickness could effectively increase soil moisture content in upper soil layer which was conducive to raise the water and nutrient use efficiency. The approach could be applied to the apple production of dryland orchard.

[Controlling effects of dual mulching on soil moisture in an apple orchard]

To investigate the controlling effects of dual mulching on soil moisture in an apple orchard on the Weibei rainfed highland, soil moisture in the 0-600 cm soil profile of the apple orchard was measured under four mulching treatments (plastic film plus straw, plastic film and straw mulches, as well as a non-mulching control) , and meanwhile the apple yield and branch growth increment were analyzed statistically. Results showed that the dual mulching treatment had the best effect on soil moisture conservation, and the soil water storage in such a soil profile was 6.7% higher than the control treatment. Long-term dual mulching could effectively alleviate soil desiccation occurring in deep soil layer in the region, and the monthly averaged soil water storage in stable layer (240-600 cm) was 64.22 mm higher than that of the control treatment. Both plastic film plus straw and plastic film mulches were able to reduce the temporal fluctuation of soil moisture in shallow soil (0-60 cm) and enhance the temporal stability of soil moisture in the layer. Compared with the single mulching treatments, the dual mulching treatment could effectively decrease the vertical variation of soil moisture in the profile and improve the stability of the vertical soil moisture distribution. The apple yield under the dual mulching treatment was evidently increased by 48.2%, as compared with the control treatment. All the analyses showed that dual mulching had more advantages in controlling soil moisture and improving apple yield than single mulching.

TET family proteins: new players in gliomas

DNA methylation at the 5-position of cytosine (5mC) in the mammalian genome has emerged as a pivotal epigenetic event that plays important roles in development, aging and disease. The three members of the TET protein family, which convert 5mC to 5-hydroxymethylcytosine, has provided a potential mechanism resulting in DNA demethylation and maintaining cellular identity. Recent studies have shown that epigenetic modifications play a key role in the regulation of the molecular pathogenesis of gliomas. In this review we focus on demonstrating the TET proteins in DNA demethylation and transcriptional regulation of different target genes. In addition, we address the role of TET proteins in gliomas. This review will provide valuable insights into the potential targets of gliomas, and may open the possibility of novel therapeutic approaches to this fatal disease.

Synthesis and X-ray Crystal Structure of Novel (3E,4E)-1-aryl-3,4-bis[(benzo[d][1,3]dioxol-5-yl)methylidene]pyrrolidene-2,5-dione

A series of novel (3E,4E)-1-aryl-3,4-bis[(benzo[d][1,3]dioxol-5-yl)methylidene]pyrrolidene-2,5-dione derivatives was synthesised and characterised by IR, 1H NMR and HRMS. Moreover, the molecular structure of (3E,4E)-3,4-bis [(benzo[d][1,3]dioxol-5-yl)methylene]-1-(4-ethoxyphenyl)pyrrolidine-2,5-dione was confirmed by the X-ray crystal structure determination.

[Allelopathic effects of Artemisia sacrorum population in typical steppe based on niche theory]

By using modified Levins niche width index and Pianka niche overlap index, this paper analyzed the ecological competition between constructive and dominant species in a typical steppe. The stem- and leaf extracts from the constructive species (Artemisia sacrorum) were utilized to study their allelopathic potential on the seed germination and plant growth of the dominant species (Stipa bungeana, Thymus mongolicus, S. grandis, and Leymus secalinus), and the ecological position of A. sacrorum in the steppe succession. In the steppe, S. bungeana had the widest niche width (0.99), followed by T. mongolicus (0.94), A. sacrorum (0.82), S. grandis (0.76), and L. secalinus (0.73). The niche overlap value between A. sacrorum and S. bungeana, S. bungeana and T. mongolicus, T. mongolicus and S. grandis, and A. sacrorum and T. mongolicus was 0.90, 0.95, 0.94, and 0.86, respectively. The allelopathic effects of A. sacrorum extracts varied with their concentration. For the seed germination, root growth, and shoot growth of the dominant species, A. sacrorum extracts showed a trend of promoting at low concentrations and inhibiting at high concentrations. The extracts of A. sacrorum had a stronger promotion effect on the root growth of S. bungeana than on that of T. mongolicus, but a stronger inhibition effect on the shoot growth of T. mongolicus than on that of S. bungeana. Methanol extracts had stronger allelopathic effects than aqueous extracts. The high niche overlap between A. sacrorum and S. bungeana, and T. mongolicus and S. grandis indicated that the steppe community would continue succession to S. bungeana, while A. sacrorum population was only an important transitional stage during the succession. The allelopathic effect of A. sacrorum played a driving role in the succession process.

[Food security in 'Grain for Green Project' area of North Shaanxi based on households]

This paper analyzed the food production by the households in the counties with high population (Mizhi County) and low population (Wuqi County) in North Shaanxi, and studied the food security and its affecting factors in the two counties by using minimum cropland area per capita and Cobb-Douglass production function methods. The results demonstrated that the food production in low population county could meet the basic standard of food security, while that in high population county could not. Cultivated area and investment in agricultural technology were the major factors affecting food security; labor force, labor quality, and grain subsidy also had positive effects on food production. The current technology and labor quality did not reach their potential for food production. This region needed to increase grain production area to reach the minimum standard of 0.14 bm2 per capita, put much stress on labor force training, and formulate appropriate following policies for 'Grain for Green' to realize the food security strategy.

(E)-2,4-Dichloro-6-{1-[(2-chloroethyl)imino]ethyl}phenol

The title Schiff base compound, C₁₀H₁₀Cl₃NO, was prepared by the condensation of 1-(3,5-dichloro-2-hy­droxy­phen­yl)ethanone with chloro­ethyl­amine. The imine adopts an E configuration with respect to the C=N bond. The H atom of the phenolic OH group is disordered over two positions with site occupation factors of 0.52 (7) and 0.48 (7), respectively, and the major occupancy component is involved in an intramolecular N—H⋯O hydrogen bond. The compound therefore exists in an iminium–phenolate as well as in the imino–phenol form. In the crystal, mol­ecules are connected by C—H⋯O and C—H⋯Cl hydrogen bonds and Cl⋯Cl inter­actions [3.7864 (9) Å] into a three-dimensional network. In addition, inter­molecular π–π stacking inter­actions [centroid–centroid distance = 4.4312 (9) Å] are observed.

4-(o-Tolyl-amino)-benzaldehyde

In the title compound, C₁₄H₁₃NO, the dihedral angle between the aromatic rings is 49.64 (18)°. The crystal structure is stabilized by N—H⋯O, C—H⋯O and C—H⋯π hydrogen bonds.

4-(p-Tolyl-amino)-benzaldehyde

In the title compound, C₁₄H₁₃NO, the dihedral angle between the aromatic rings is 66.08 (9)°. Chains are formed along the b axis through inter­molecular N—H⋯O hydrogen bonds. The crystal structure is further stabilized by C—H⋯π inter­actions.

2-[5-(1,3-Benzodioxol-5-yl)-3-ferrocenyl-4,5-dihydro-1H-pyrazol-1-yl]-4-phenyl-1,3-thiazole

In the title compound, [Fe(C₅H₅)(C₂₄H₁₈N₃O₂S)], the pyrazoline ring adopts a twist conformation. The thia­zole ring forms dihedral angles of 83.7 (2) and 34.4 (2)° with the benzene ring of the benzodioxole ring and the fused phenyl ring, respectively. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯π inter­action. The crystal packing features inter­molecular C—H⋯N, C—H⋯O hydrogen bonds and weak C—H⋯π inter­actions.

The synthesis, X-ray crystal structure and optical properties of novel 1-ferrocenyl-2-(3-phenyl-1H-1,2,4-triazol-5-ylthio)ethanone derivatives

A series of novel 1-ferrocenyl-2-(3-phenyl-1H-1,2,4-triazol-5-ylthio)ethanone derivatives was synthesized by the reaction of 3-substituted-1H-1,2,4-triazole-5-thiol and chloroacetyl ferrocene in the presence of sodium hydride and potassium iodide at reflux. The structures of the new compounds were determined by IR and (1)H NMR spectroscopy and HRMS. The structure of compound 5c was established by X-ray crystallography. UV-vis absorption and fluorescence spectra were recorded in ethanol and dichloromethane. The results showed that compounds 5a-g display similar absorptions ranging from 300 to 500nm and maximal emission bands are about 566nm. The intensity of fluorescence and maximal emission bands are dependent on the groups bonded to triazole rings.

[Effects of different patterns surface mulching on soil properties and fruit trees growth and yield in an apple orchard]

Taking a nine-year-old Fuji apple orchard in Loess Plateau as test object, this paper studied the effects of different patterns surface mulching (clean tillage, grass cover, plastic film mulch, straw mulch, and gravel mulch) on the soil properties and fruit trees growth and yield in this orchard. Grass cover induced the lowest differentiation of soil moisture profile, while gravel mulch induced the highest one. In treatment gravel mulch, the soil moisture content in apple trees root zone was the highest, which meant that there was more water available to apple trees. Surface mulching had significant effects on soil temperature, and generally resulted in a decrease in the maximum soil temperature. The exception was treatment plastic film mulch, in which, the soil temperature in summer exceeded the maximum allowable temperature for continuous root growth and physiological function. With the exception of treatment plastic film mulch, surface mulching increased the soil CO2 flux, which was the highest in treatment grass cover. Surface mulching also affected the proportion of various branch types and fruit yield. The proportion of medium-sized branches and fruit yield were the highest in treatment gravel mulch, while the fruit yield was the lowest in treatment grass cover. Factor analysis indicated that among the test surface mulching patterns, gravel mulch was most suitable for the apple orchards in gully region of Loess Plateau.

[Simultaneous determination of PAHs in food by low-temperature constant-energy synchronous fluorescence spectrometry]

The authors developed a rapid analytical method that could determine the PAHs in food samples simultaneously by the coupled approach of Shpol' skii spectroscopy and constant-energy synchronous fluorescence scanning technique. Low-fat food samples, which were just extracted with octane and high-fat food samples pre-processed with saponification and extracting, could be analyzed immediately. The recoveries ranged from 80.2% to 98.9% and the correlation coefficients of the linearity were higher than 0.993 8. This method was selective, simple, rapid and inexpensive.

2-(4-Chloro-phen-yl)-5-(3,4-dimethoxy-pheneth-yl)-6,7-dihydro-pyrazolo[1,5-a]pyrazin-4(5H)-one

In the title compound, C₂₂H₂₂ClN₃O₃, the dihedral angles between the planes of the benzene rings and the pyrazole ring are 16.05 (10) and 84.84 (10)°. The conformation of the six-membered heterocyclic ring is close to a screw-boat. The crystal packing is stabilized by weak inter­molecular C—H⋯O inter­actions and is also consolidated by C—H⋯π inter­actions.

9-O-Butyl-berberrubinium bromide

In the title compound, C₂₃H₂₄NO₄⁺·Br⁻, the butyl chain is disordered between two conformations; the occupancies refined to 0.735 (7) and 0.265 (7). The dihedral angle between the naphthalene ring system and the phenyl ring is 11.6 (2)°. In the crystal structure, the cations are packed via π–π inter­actions into stacks propagating in the [010] direction. Weak inter­molecular C—H⋯O and C—H⋯Br hydrogen bonds contribute further to the crystal packing stability.

1-(4-tert-Butyl-benz-yl)-3-phenyl-1H-pyrazole-5-carboxylic acid

In the title compound, C₂₁H₂₂N₂O₂, the mean plane of the pyrazole ring makes dihedral angles of 18.80 (12) and 77.13 (5)°, respectively, with the mean planes of the phenyl and tert-butyl­benzyl rings. The carboxylate group is inclined at 8.51 (14)° with respect to the pyrazole ring. The crystal structure displays inter­molecular O—H⋯O hydrogen bonding, generating centrosymmetric dimers.

4-Benzyl-7-chloro-2H-1,4-benz-oxazin-3(4H)-one

In the title compound, C₁₅H₁₂ClNO₂, the two benzene rings are nearly perpendicular to each other [dihedral angle = 89.99 (13)°]. The O atom of the six-membered heterocyclic ring is disordered over two sites in a ratio of 0.46 (4):0.54 (4) and is displaced from the mean plane formed by other five atoms, resulting an envelope conformation of the six-membered hetercycle ring.

N-Benzyl-2-(2-chloro-5-methylphenoxy)acetamide

The asymmetric unit of the title compound, C₁₆H₁₆ClNO₂, contains two crystallographically independent mol­ecules, which differ mainly in the orientation of the benzyl group with respect to the rest of the mol­ecule. In the crystal packing, centrosymmetrically related mol­ecules are linked into dimers via inter­molecular C—H⋯O hydrogen-bond inter­actions.

6-Chloro-2H-1,4-benzoxazin-3(4H)-one

In the title compound, C₈H₆ClNO₂, the conformation of the six-membered heterocyclic ring is close to screw boat and the mol­ecules are linked via inter­molecular N—H⋯O hydrogen bonds along the b axis.

Synthesis and preliminary biological evaluation of novel pyrazolo[1,5-a]pyrazin-4(5H)-one derivatives as potential agents against A549 lung cancer cells

A series of novel pyrazolo[1,5-a]pyrazin-4(5H)-one derivatives were synthesized by the reaction of ethyl 3-aryl-1-(2-bromoethyl)-1H-pyrazole-5-carboxylate and amine in the general heating condition and microwave-assisted condition. The structures of the compounds were determined by IR, (1)H NMR and mass spectroscopy, in addition, representative single-crystal structures were characterized by using X-ray diffraction analysis. Preliminary biological evaluation showed that the compounds could inhibit the growth of A549 cells in dosage- and time-dependent manners. The study on structure-activity relationships showed that compounds with 4-chlorophenyl group at pyrazole moiety, such as 5-benzyl-2-(4-chlorophenyl)-6,7-dihydropyrazolo[1,5-a]pyrazin-4(5H)-one (3o) had much more inhibitory effects. Compound 3o was the most effective small molecule in inhibiting A549 cell growth and might perform its action through modulating autophagy.

[Predictive and diagnostic value of fibronectin levels in pregnancy-induced hypertension]

Serum fibronectin (FN) level was assayed using ELISA monoclonal antifibronectin antibody of 152 normal gravida tested in the second and third trimesters, 24 cases who showed higher serum FN (309 +/- 13 mg/l, means +/- s means) than the normal (163 +/- 4 mg/l) developed pregnancy induced hypertension (PIH) later on. The serum FN level of 30 PIH patients was significantly higher than that of 128 normal gravidae (P less than 0.01). A serum FN level of 255 mg/l is suggested as the critical value in predicting the occurrence of PIH. The sensitivity was 79.2%, the specificity 95.3%, the index of diagnosis 174.5%, the efficiency of diagnosis 92.8%, the positive predictive value 76.0%, and the negative predictive value 96.1%.