In maize (
Zea mays
L.) production, grain-filling stage is a pivotal phase that drought occurring would irreversibly cause leaf senescence and yield loss. Meanwhile, drought induces the ...disequilibrium of carbohydrates that inevitably produces the toxic substance methylglyoxal (MG) that plays dual roles including cytotoxic metabolite or signaling molecule in plants. However, how exogenous MG influences maize yield formation in response to drought during grain filling remains unknown. In this study, maize plants were exposed to moderate and severe drought conditions from 15 to 28 days after pollination with foliar spraying of MG (0, 15, 25, and 35 mM). Notably, MG application significantly increased kernel number and retrieved yield loss by 14–48% under drought, demonstrating an increased resistance of the plants. Interestingly, high (25–35 mM) and low concentrations (15–25 mM) of MG application under moderate and severe drought performed the highest yield output, respectively. To investigate the mechanisms by which MG enhanced drought resistance, we confirmed that MG application postponed leaf senescence under both drought conditions and significantly improved photosynthesis under severe drought during filling stage. Specifically, MG application escalated the levels of soluble sugar and sucrose while suppressing endogenous MG accumulation by activating glyoxalase system in leaf during the early phase of drought stress and well-watered condition. Collectively, these results demonstrate that exogenous MG application enhances drought tolerance during maize grain filling, possibly through regulation on the homeostasis of endogenous MG and sugars. These findings provide a new approach to secure yield against drought stress in maize production.
We study far-field angular radiation patterns of second harmonic generation (SHG) from gold nanosphere, nanocube, nanorod, and nanocup illuminated by tightly focused linearly and radially polarized ...beams, respectively. It is found that under linearly polarized illumination, far-field forward-scattering SHG (FSHG) dominates second harmonic (SH) responses generated by those gold particles. On the contrary, it is amazing that significant backward-scattering SHG (BSHG) can be observed when those gold nanoparticles are excited by a focused radially polarized beam. For the case of gold nanosphere, the effective point dipole systems are developed to reasonably elucidate this interesting difference. Our investigations suggest that for SHG microscopy with backward detection scheme, tightly focused radially polarized beam could be a promising excitation field to improve the backward SH signal.
Flexible conductive hydrogel has been driven by scientific breakthroughs and offers a wide variety of applications, including sensors, electronic skins, biomedicine, energy storage, etc. Based on the ...mixed-ion crosslinking method, gelatin and sodium alginate (Gel-Alg) composite hydrogels were successfully prepared using Casup.2+ crosslinking. The migration behavior of berberine hydrochloride (BBH) in the matrix network structure of Gel-Alg hydrogel with a certain pore size under an electric field was studied, and the transdermal effect of berberine hydrochloride under an electric field was also studied. The experimental results show that Gel-Alg has good flexibility and conductivity, and electrical stimulation can enhance the transdermal effect of drugs. Gel-Alg composite hydrogel may be a new material with potential application value in future biomedical directions.
ABSTRACT
In the conclusion part of an academic paper, sentences concerning future research provide an outlook about future focus of research and reflect the latest development trend in a specific ...topic or field. These sentences are of high value for further investigation. However, very little has been done on sentences talking about future research in academic full texts. Here, papers in JASIST were studied with respect to these sentences. Deep learning model was trained on articles containing sentences annotated as relating to “future research” by BERT model. The model capable of automatic extraction of such sentences from academic full texts was obtained. Later this model was verified on the unannotated corpus, which demonstrated good performance. Finally, clustering was performed for the extracted sentences. It was found by cluster analysis that the sentences concerning future research were divided into four types. Our findings provide support for classification of sentences concerning future research.
This paper presents the development and evaluation of a high-volume, multiple rectangular (slit) geometry jet impactor. Operating with a preselective inlet that removes particles larger than
2.5
μm
...in aerodynamic size, the impactor has been designed to separate ultrafine (
<0.15
μm
) from the accumulation mode range (
0.15<d
p
<2.5
μm
). Particles are accelerated by passing through 10 parallel slits nozzles, each
12.5
cm
long by
0.0125
cm
wide. The average jet velocity in each rectangular jet is approximately
5800
cm
s
−1
. Following acceleration, particles larger than approximately
0.15
μm
impact on quartz fiber strips, each
12.5×0.5
cm
2
, while the aerosol fraction smaller than
0.15
μm
penetrates through the outlet of the impactor. The impactor operates at a flow rate
550
l
min
−1
and at a very low pressure drop of
0.020
kPa
. The performance of the multi-slit impactor was validated in laboratory and the field tests. Laboratory experiments conducted with monodisperse PSL particles as well as polydisperse ammonium nitrate, sulfate and indoor aerosols corroborated the 50% cutpoint of the impactor at
0.15
μm
. Field test comparisons between the high-volume multi-slit impactor and the Microorifice Uniform Deposit Impactor (MOUDI) showed that the accumulation and ultrafine mode concentrations of particulate nitrate, sulfate, elemental and organic carbon are in very good agreement (within 10% or less). This impactor has been developed primarily as a separator of ultrafine from accumulation mode particles for use in human exposure studies to concentrated ambient ultrafine aerosols. High-volume collection of size-fractionated particulate matter accomplished by this impactor further enables investigators in the field of environmental health to conduct toxicological studies using ambient accumulation and ultrafine mode particles in vitro as well as by means of intratracheal instillation.
Abscisic acid (ABA) accumulates in plants under drought stress, but views on the role of ABA in kernel formation and abortion are not unified. The response of the developing maize kernel to exogenous ...ABA was investigated by excising kernels from cob sections at four days after pollination and culturing in vitro with different concentrations of ABA (0, 5, 10, 100μM). When ABA was applied at the early post-pollination stage (EPPS), significant weight loss was observed at high ABA concentration (100μM), which could be attributed to jointly affected sink capacity and activity. Endosperm cells and starch granules were decreased significantly with high concentration, and ABA inhibited the activities of soluble acid invertase and acid cell wall invertase, together with earlier attainment of peak values. When ABA was applied at the middle post-pollination stage (MPPS), kernel weight was observably reduced with high concentration and mildly increased with low concentration, which was regulated due to sink activity. The inhibitory effect of high concentration and the mild stimulatory effect of low concentration on sucrose synthase and starch synthase activities were noted, but a peak level of ADP-glucose pyrophosphorylase (AGPase) was stimulated in all ABA treatments. Interestingly, AGPase peak values were advanced by low concentration and postponed by high concentration. In addition, compared with the control, the weight of low ABA concentration treatments were not statistically significant at the two stages, whereas weight loss from high concentration applied at EPPS was considerably obvious compared with that of the MPPS, but neither led to kernel abortion. The temporal- and dose-dependent impacts of ABA reveal a complex process of maize kernel growth and development.
This study develops a one-dimensional analytical solution for contaminant advection, diffusion and adsorption through a soil–bentonite (SB)/geosynthetic clay liner (GCL)/SB–aquifer composite cutoff ...wall (CCW) system. The solution agrees well with an existing double-layer model. Adopting toluene as a representative contaminant, using the present solution, the analysis systematically investigates the impact of hydraulic gradient (i) and the hydraulic conductivities of GCL (kgcl) and SB (ksb). The results show the following: (1) Increasing i from 0.1 to 1 reduces the concentration breakthrough time (tcb) from 20 to 11 years and mass flux breakthrough time (tfb) from infinite to 11 years, indicating lower i significantly extend both tcb and tfb, which is crucial for optimizing CCW barrier performance; (2) lowering kgcl from 5.0 × 10−11 m/s to 1 × 10−12 m/s and reducing ksb from 1.0 × 10−9 m/s to 1.0 × 10−11 m/s, would increase the tcb by 36% and 100%, respectively. It demonstrates that reducing kgcl and ksb could enhance barrier performance. (3) To achieve equivalent barrier performance, soil–bentonite cutoff wall (SBCW) requires greater thickness compared to SB/GCL/SB CCW, indicating that GCL reduces the required amount of bentonite; and (4) CCWs can use SB with lower adsorption capacity to achieve equivalent performance, further reducing bentonite requirements. The present solution can aid in the design and optimization of GCL-enhanced CCWs.
•Foliar application of BA or BR at tasseling increased endogenous ZR and BR in kernel.•Endosperm cell number was significantly accelerated by exogenous BA and BR.•The enhanced capacity of source and ...sink stimulated grain filling rate, resulting in high grain weight and grain yield.•The lag stage of kernel development played an important role in sink establishment and grain filling.
The endosperm contributes approximately 80% of the final kernel weight in maize. Plant hormones that affect cell proliferation might increase endosperm cells and establish greater kernel sink capacity, which would improve grain yield. In this study, 6-benzyladenine (BA) and brassinolide (BR) were separately sprayed at tasseling to regulate kernel endosperm cell division, and EDAH (a mixture of ethephon and diethyl aminoethyl hexanoate) was foliar applied at the jointing stage to enhance lodging resistance. The results showed that the two hormones sprayed at tasseling could hamper leaf senescence, improve photosynthesis and significantly increase the number of kernel endosperm cells by 6.2-40.4%, resulting in a high grain filling rate and high kernel weight. Additionally, the tasseling treatments increased grain yield by 2.9-16.0% in both years. There were no significant differences between EDAH and control conditions in sink capacity and yield. The correlation analysis suggested that grain weight and yield had a close correlation with the number of endosperm cells and the filling rate in the lag stage. We concluded that the lag stage played a vital role in constructing sink capacity, and treating maize with BA or BR at tasseling can apparently increase the source and sink capacity to improve the grain filling rate and yield.
Osteoarthritis (OA) is a serious problem in the recent aging society, and early diagnosis and intervention of articular cartilage degeneration are very important for the onset of OA. Therefore, ...development of newer MRI techniques is necessary and expected for detection of early articular cartilage degeneration.
24 rabbits were randomly divided into four equal experimental groups (Group A, B, C, D) to establish articular cartilage models in different grades of early degeneration by injecting papain into the left knee joint cavity. Another 8 rabbits were considered as blank control (Group E), and then randomized into four subgroups (EA, EB, EC, ED). T1ρ and T2-weighted images of the bilateral knee joints were obtained for rabbits by using 3.0 T MRI. Group A, B, C, and D were imaged respectively at 1, 2, 3, and 4 weeks post-operation, and EA, EB, EC, ED underwent the same period imaging. Rabbits were sacrificed after scanning and the femoral condyle cartilage (FCC) was histological examined. T1ρ values of the femoral condyle cartilage were measured and statistically analyzed, and contrasted with the histologic results.
T1ρ values of the left side in experimental groups were significantly higher than the right side (P < 0.05), and which increased gradually with the passage of post-operation time (P < 0.05). Histological examination demonstrated the proteoglycan content of the left side decreased, and indicated the occurrence of early degeneration.
T1ρ MRI can sensitively and quantitatively reflect the change in proteoglycans prior to the morphologic alterations of articular cartilage, and T1ρ value is gradually increased with a decrease in proteoglycan content, therefore that T1ρ could potentially act as a reliable tool to identify early cartilage degeneration.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
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