Crop rotations increased soil ecosystem multifunctionality by improving keystone taxa and soil properties in potatoes.

Continuous cropping of the same crop leads to soil degradation and a decline in crop production, and these impacts could be mitigated through rotation cropping. Although crop rotation enhances soil fertility, microbial community diversity, and potato yield, its effects on the soil ecosystem multifunctionality (EMF) remain unclear. In the present research, we comparatively examined the effects of potato continuous cropping (PP) and rotation cropping [potato-oat rotation (PO) and potato-forage maize rotation (PFM)] on the soil EMF as well as the roles of keystone taxa, microbes abundance, and chemical properties in EMF improvement. It was demonstrated that soil EMF is increased in rotation cropping (PO and PFM) than PP. Soil pH was higher in rotation cropping (PO and PFM) than in PP, while total phosphorus (TP) and available phosphorus (AP) were significantly decreased than that in PP. Rotation cropping (PO and PFM) markedly changed the bacterial and fungal community compositions, and improved the potential plant-beneficial fungi, e.g., Schizothecium and Chaetomium, while reducing the abundances of the potentially phytopathogenic fungi, e.g., Alternaria, Fusarium, Verticillium dahiae, Gibberella, Plectosphaerella, Colletotrichum, Phoma, and Lectera in comparison with PP. Also, co-occurrence patterns for bacteria and fungi were impacted by crop rotation, and keystone taxa, e.g., Nitrospira.1, Lysinibacillus, Microlunatus.1, Sphingomonas.3, Bryobacter.1, Micromonospora, and Schizothecium, were enriched in PO and PFM than PP. The structural equation model (SEM) further demonstrated that cropping systems increased soil ecosystem multifunctionality through regulating SOM and keystone taxa (Schizothecium1), and keystone taxa were mediated by soil pH. This study suggested that rotation cropping might contribute to the improvement of soil ecosystem multifunctionality as well as the development of disease-suppressive soils in comparison with potato continuous cropping.

Reducing the carbon footprint per unit of economic benefit is a new method to accomplish low-carbon agriculture. A case study: adjustment of the planting structure in Zhangbei County, China.

BACKGROUND: The development of low-carbon agriculture is promising for mitigating climate change. This study used adjustments to the planting structure in Zhangbei County, China, as an example to evaluate whether the carbon footprint per unit of economic benefit is a suitable indicator of low-carbon agriculture and to determine if low-carbon agriculture is not necessarily low-input non-intensive agriculture. RESULTS: The results showed that total greenhouse gas emissions increased; therefore, the adjustments to the planting structure were ostensibly not a low-carbon process. However, if we obtain the same economic benefit as the actual distribution of the planting industry by adopting the scenario of planting only grain crops, then the annual greenhouse gas emissions would be 1608.00 × 103  t CO2 eq, and 5769.94 × 103  ha of farmland would be required. However, if we adopt the scenario of planting only vegetable crops, then only 82.52 × 103  ha of farmland would be required, and the annual greenhouse gas emissions would be 323.52 × 103  t CO2 eq. CONCLUSIONS: These results indicated that the carbon footprint per unit of economic benefit is a suitable indicator to assess agricultural sustainability and that intensive agriculture with high input and high output is a form of low-carbon agriculture if the carbon footprint per unit of economic benefit is low. © 2019 Society of Chemical Industry.

Age estimation based on pulp cavity/chamber volume of 13 types of tooth from cone beam computed tomography images.

AIM: The aims of this study are to identify which type of tooth has the strong relationship between age and pulp cavity/chamber volume among 13 types of tooth from the same dentition and to determine whether the inclusion of multiple types of tooth may improve the accuracy of age estimation. MATERIALS AND METHODS: Cone beam computed tomography (CBCT) images from 115 females and 125 males aged between 16 and 63 years were analyzed. The DICOM data of all the images were imported into ITK-SNAP 2.4 for the calculation of pulp cavity/chamber volumes. Logarithmic regression analysis and multiple linear regression analysis were applied to establish the relationship between age and pulp cavity/chamber volumes. RESULTS: Among the 13 types of tooth, maxillary second molars have the largest R (2) (0.491, 0.642, and 0.498) and the smallest SEE (8.119, 6.754, and 8.022) in male, female, and pooled gender samples, respectively. The multiple linear regression analysis for the combination of multi-types of tooth indicated that a larger R (2) (0.627, 0.701, and 0.631) and smaller SEE (7.100, 6.258, and 6.970) than the counterpart calculated from the logarithmic regression analysis of a single type of tooth in male, female, and pooled gender samples, respectively. CONCLUSION: The pulp chamber volume of the maxillary second molars has the largest correlation coefficient with age. Using multiple types of tooth may improve the accuracy of age estimation compared with only one type of tooth used.

Ultrasensitive sensing platform for platelet-derived growth factor BB detection based on layered molybdenum selenide-graphene composites and Exonuclease III assisted signal amplification.

A highly sensitive and ultrasensitive electrochemical aptasensor for platelet-derived growth factor BB (PDGF-BB) detection is fabricated based on layered molybdenum selenide-graphene (MoSe2-Gr) composites and Exonuclease III (Exo III)-aided signal amplification. MoSe2-Gr is prepared by a simple hydrothermal method and used as a promising sensing platform. Exo III has a specifical exo-deoxyribonuclease activity for duplex DNAs in the direction from 3' to 5' terminus, however its activity is limited on the duplex DNAs with more than 4 mismatched terminal bases at 3' ends. Herein, aptamer and complementary DNA (cDNA) sequences are designed with four thymine bases on 3' ends. In the presence of target protein, the aptamer associates with it and facilitates the formation of duplex DNA between cDNA and signal DNA. The duplex DNA then is digested by Exo III and releases cDNA, which hybridizes with signal DNA to perform a new cleavage process. Nevertheless, in the absence of target protein, the aptamer hybridizes with cDNA will inhibit the Exo III-assisted nucleotides cleavage. The signal DNA then hybridizes with capture DNA on the electrode. Subsequently, horse radish peroxidase is fixed on electrode by avidin-biotin reaction and then catalyzes hydrogen peroxide and hydroquinone to produce electrochemical response. Therefore, a bridge can be established between the concentration of target protein and the degree of the attenuation of the obtained signal, providing a quantitative measure of target protein with a broad detection range of 0.0001-1 nM and a detection limit of 20 fM.

Age estimation based on pulp chamber volume of first molars from cone-beam computed tomography images.

AIM: To establish a method that can be used for human age estimation on the basis of pulp chamber volume of first molars and to identify whether the method is good enough for age estimation in real human cases. MATERIALS AND METHODS: CBCT images of 373 maxillary first molars and 372 mandibular first molars were collected to establish the mathematical model from 190 female and 213 male patients whose age between 12 and 69 years old. The inclusion criteria of the first molars were: no caries, no excessive tooth wear, no dental restorations, no artifacts due to metal restorative materials present in adjacent teeth, and no pulpal calcification. All the CBCT images were acquired with a CBCT unit NewTom VG (Quantitative Radiology, Verona, Italy) and reconstructed with a voxel-size of 0.15mm. The images were subsequently exported as DICOM data sets and imported into an open source 3D image semi-automatic segmenting and voxel-counting software ITK-SNAP 2.4 for the calculation of pulp chamber volumes. A logarithmic regression analysis was conducted with age as dependent variable and pulp chamber volume as independent variables to establish a mathematical model for the human age estimation. To identify the precision and accuracy of the model for human age estimation, another 104 maxillary first molars and 103 mandibular first molars from 55 female and 57 male patients whose age between 12 and 67 years old were collected, too. Mean absolute error and root mean square error between the actual age and estimated age were used to determine the precision and accuracy of the mathematical model. The study was approved by the Institutional Review Board of Peking University School and Hospital of Stomatology. RESULTS: A mathematical model was suggested for: AGE=117.691-26.442×ln (pulp chamber volume). The regression was statistically significant (p=0.000<0.01). The coefficient of determination (R(2)) was 0.564. There is a mean absolute error of 8.122 and root mean square error of 5.603 between the actual age and estimated age for all the tested teeth. CONCLUSION: The pulp chamber volume of first molar is a useful index for the estimation of human age with reasonable precision and accuracy.

Iron-catalyzed aerobic C-H functionalization of pyrrolones.

The aerobic oxidation of pyrrolones catalyzed by Fe(OTf)3 to form reactive N-acyliminium ion intermediates that undergo nucleophilic additions with alcohols to give the corresponding products in moderate to good yields is described.

Aptamer/Au nanoparticles/cobalt sulfide nanosheets biosensor for 17ß-estradiol detection using a guanine-rich complementary DNA sequence for signal amplification.

We have developed a sensitive sensing platform for 17ß-estradiol by combining the aptamer probe and hybridization reaction. In this assay, 2-dimensional cobalt sulfide nanosheet (CoS) was synthesized by a simple hydrothermal method with L-cysteine as sulfur donor. An electrochemical aptamer biosensor was constructed by assembling a thiol group tagged 17ß-estradiol aptamer on CoS and gold nanoparticles (AuNPs) modified electrode. Methylene blue was applied as a tracer and a guanine-rich complementary DNA sequence was designed to bind with the unbound 17ß-estradiol aptamer for signal amplification. The binding of guanine-rich DNA to the aptamer was inhibited when the aptamer captured 17ß-estradiol. Using guanine-rich DNA in the assay greatly amplified the redox signal of methylene blue bound to the detection probe. The CoS/AuNPs film formed on the biosensor surface appeared to be a good conductor for accelerating the electron transfer. The method demonstrated a high sensitivity of detection with the dynamic concentration range spanning from 1.0×10(-9) to 1.0×10(-12) M and a detection limit of 7.0×10(-13) M. Besides, the fabricated biosensor exhibited good selectivity toward 17ß-estradiol even when interferents were presented at 100-fold concentrations. Our attempt will extend the application of the CoS nanosheet and this signal amplification assay to biosensing areas.

Measurement accuracy of temporomandibular joint space in Promax 3-dimensional cone-beam computerized tomography images.

OBJECTIVE: The aim of this study was to evaluate and compare the measurement accuracy of the temporomandibular joint (TMJ) space in the Promax 3D cone-beam computerized tomography (CBCT) images scanned with 2 different dental protocols. STUDY DESIGN: TMJ space impression models were made according to the occlusion. Forty joints were scanned with the standard and the large view protocol of the Promax 3D CBCT scanner. Two observers measured the joint spaces 3 times on both radiographs and the photocopies of the impression models. RESULTS: A total of 120 CBCT images were measured. There were no significant differences among the actual joint spaces and the CBCT measurements performed with the 2 scanning protocols (P = .305). The inter- and intraobserver variabilities were not significant. CONCLUSIONS: The 2 scanning protocols provided by the Promax 3D CBCT scanner were reliable and similar for recording the TMJ space.

Greatly enhanced energy density and patterned films induced by photo cross-linking of poly(vinylidene fluoride-chlorotrifluoroethylene).

Greatly enhanced energy density in poly(vinylidene fluoride-chlorotrifluoroethylene) [P(VDF-CTFE)] is realized through interface effects induced by a photo cross-linking method. Being different from nanocomposites with lowered dielectric strength, the cross-linked P(VDF-CTFE)s possess a high breakdown field as well as remarkably elevated polarization, both of which contribute to the enhanced energy density as high as 22.5 J · cm(-3). Moreover, patterned thin films with various shapes and sizes are fabricated by photolithography, which sheds new light on the integration of PVDF-based electroactive polymers into organic microelectronic devices such as flexible pyroelectric/piezoelectric sensor arrays or non-volatile ferroelectric memory devices.

[The application of radiological image in forensic medicine].

Personal identification is an important work in forensic investigation included sex discrimination, age and stature estimation. Human identification depended on radiological image technique analysis is a practice and proper method in forensic science field. This paper intended to understand the advantage and defect by reviewed the employing of forensic radiology in forensic science field broadly and provide a reference to perfect the application of forensic radiology in forensic science field.