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This paper deals with the existence and multiplicity of convex radial solutions for the Monge-Amp$ \grave{\text e} $re equation involving the gradient $ \nabla u $: $ \begin{cases} \det (D^2u) = f(|x|, -u, |\nabla u|), x\in B, \\ u|_{\partial B} = 0, \end{cases} $ where $ B: = \{x\in \mathbb R^N: |x| < 1\} $. The fixed point index theory is employed in the proofs of the main results.

Government subsidies play a crucial role in optimizing industrial structures, eliminating outdated production capacities, and facilitating industrial transformation and upgrading in traditional industries. This paper is based on data collected from 112 sources, including 26 listed companies in China's steel industry and 30 companies in the photovoltaic sector, during the period from 2019 to 2020. Utilizing the three-stage undesirable output SBM model, we examine the impact of government subsidies on input-output slack and production efficiency. We find that the production efficiency of steel enterprises and photovoltaic enterprises is seriously polarized after considering the undesirable output, and the production efficiency of relatively small enterprises is high for the steel industry. In an unstable economic environment, it is advisable for the government to provide pre-subsidies to steel enterprises to assist them in adjusting resource allocation and effectively responding to unforeseen events. Regardless of the economic conditions, photovoltaic enterprises rely more on post-subsidies to mitigate personnel and technology investment slack. Overall, this study sheds light on the effectiveness of government subsidies in driving efficiency improvements in traditional and emerging industries.

Nano-optomechanical systems plays an indispensable role in all-optical manipulation of light but high energy losses severely limit their development. Here the authors show ultrafast all-optical manipulation in a sub-5 nm tip-supported optomechanical metasurface.

In this article, the observations from two different experimental studies on CO2 two-phase flow regimes in a near horizontal pipe are analysed. These experiments show significant bubble entrainment in a stratified flow, and the bubble entrainment in liquid is found to be a dominant mechanism for the flow regime transition between the stratified and bubbly flow. The hydrodynamic slug flow is not observed in these experimental studies. The X-ray measurement of the experimental study in a near horizontal pipe of 44 mm internal diameter is processed to obtain the bubble volume fraction in the liquid layer, which is found to be a function of two-phase Froude number. This Froude number definition takes into account gas density and pipe inclination effects. A parametric study shows that the bubble entrainment into the liquid layer decreases significantly with an increase of pipe internal diameter.

Myocardial ischemia is a predominant cardiovascular disorder that can result in a series of life-threatening cardiovascular diseases. Carthami flos (CF), the flower of Carthamus tinctorius L., is a commonly used herbal medicine in Chinese medicine for treating coronary atherosclerotic heart diseases based on its anti-myocardial ischemia (MI) effects. This paper aimed to investigate the active substances and mechanisms of the anti-MI effects of CF by network pharmacology and in vitro experiments. The results indicated that 9 constituents showed high degree of association with multiple targets of MI, including quercetin, kaempferol, β-sitosterol, luteolin, baicalein, safflomin A, safflomin C, safflower-yellow-B and hydroxysafflor yellow A. In addition, AKT1, EGFR, CASP3, MYC, JUN, ALB, CTNNB1, VEGFA, ESR1, and IL1B were screened as the leading targets with a degree number ≥50. Bioinformatic annotation of GO-MF and KEGG showed that the anti-MI effects of CF are related to apoptosis and response to antioxidative stress pathways. The in vitro results showed that CF reduced LDH and CK levels, alleviated cell cycle arrest, and decreased ROS levels in H2O2-treated H9c2 cells. In addition, CF also promoted the nuclear shift of Nrf2 and the mRNA expressions of Akt, Nrf2 and Bcl-2 but decreased the expression of caspase-3 in H2O2-treated H9c2 cells. Collectively, the anti-MI effects of CF involve inhibiting apoptosis and antioxidative stress in cardiomyoblasts by regulating Akt/Nrf2/Caspase-3/Bcl-2, and the possible active substances of CF are quercetin, kaempferol, β-sitosterol, luteolin, baicalein, safflomin C, safflower-yellow-B, and hydroxysafflor yellow A. The results of this study will be helpful for further drug development of CF and its active monomers.

Summary: Two-dimensional (2D) chirality-induced asymmetric transmission/reflection has great potential for polarization applications. Usually, asymmetric effects resulting from circular conversion dichroism (CCD) occur in chiral metasurfaces. Here, we propose a single-layer twisted graphene-patterned (with tilted elliptical hole arrays) metasurface and theoretically reveal its tunable CCD in the terahertz (THz) region. The unit cell of the metasurface is achiral. Merely by altering the in-plane orientation of holes for structural 2D chirality, a tunable CCD can be achieved at normal incidence. Interestingly, the reflection phase can be considered an intuitive method to show this metasurface’s anisotropy, which complements the conventional CCD measurement in characterizing chiral materials. Furthermore, we can achieve active CCD based on the tunability of graphene. Due to the Fabry-Pérot resonance, a multiband enhancement of CCD spectrum will happen by changing the dielectric layer thickness. The proposed metasurface provides more flexible opportunities for designing active THz devices for polarization manipulation.

Object detection by shipborne unmanned aerial vehicles (UAVs) equipped with electro-optical (EO) sensors plays an important role in maritime rescue and ocean monitoring. However, high-precision and low-latency maritime environment small-object-detection algorithms remain a major challenge. To address this problem, this paper proposes the YOLO-BEV (“you only look once”–“bird’s-eye view”) model. First, we constructed a bidirectional feature fusion module—that is, PAN+ (Path Aggregation Network+)—adding an extremely-small-object-prediction head to deal with the large-scale variance of targets at different heights. Second, we propose a C2fSESA (Squeeze-and-Excitation Spatial Attention Based on C2f) module based on the attention mechanism to obtain richer feature information by aggregating features of different depth layers. Finally, we describe a lightweight spatial pyramid pooling structure called RGSPP (Random and Group Convolution Spatial Pyramid Pooling), which uses group convolution and random channel rearrangement to reduce the model’s computational overhead and improve its generalization ability. The article compares the YOLO-BEV model with other object-detection algorithms on the publicly available MOBDrone dataset. The research results show that the mAP0.5 value of YOLO-BEV reached 97.1%, which is 4.3% higher than that of YOLOv5, and the average precision for small objects increased by 22.2%. Additionally, the YOLO-BEV model maintained a detection speed of 48 frames per second (FPS). Consequently, the proposed method effectively balances the accuracy and efficiency of object-detection in shipborne UAV scenarios, outperforming other related techniques in shipboard UAV maritime object detection.

PurposeTo investigate the clinical characteristics, treatment, and prognosis of cryptorchid testicular torsion in children.MethodsThe clinical data of 25 children who received treatment for cryptorchid testicular torsion between January 2010 and December 2021 were retrospectively reviewed. The median age of the patients was 64.5 months (range: 2 months to 15 years). All patients had unilateral torsion, and the duration of symptoms ranged from 3 to 192 h.ResultsAmong the 25 patients, five underwent orchidopexy, while the remaining 20 underwent orchiectomy. After 6 months to 8 years of follow up, the 20 patients who had undergone orchiectomy had a well-developed testis on the healthy side. Four of the five patients who had undergone orchidopexy of the affected testis had well-developed testes bilaterally, while one experienced testicular atrophy.ConclusionCryptorchid testicular torsion is a rare urological emergency that displays a delayed presentation and is often misdiagnosed. Clinicians need to carefully review the patient's medical history and ultrasound findings and perform a thorough physical examination to make a correct diagnosis. Active testicular exploration is required for patients suspected to have cryptorchid testicular torsion, and the decision to perform orchidopexy or orchiectomy depends on the intraoperative situation.

Objective To describe standard and modified de-epithelialized Byars’ flap techniques in tubularized incised plate urethroplasty and evaluate postoperative outcomes. Methods We retrospectively evaluated data for 404 primary hypospadias repair patients who underwent standard (Group A) or modified (Group B) urethroplasty between January 2016 and 2021. Group B’s data were analyzed to evaluate whether our modified technique was effective for all hypospadias types. Results There was no difference in the ratio of different hypospadias types between Groups A (n = 145) and B (n = 259). Median follow-up duration was 35 months. Fistula occurred in 19 patients in Group A and 12 in Group B (statistically significant difference). The total complication rate was statistically significantly different between the groups. In Group B, 3/142 patients with distal hypospadias developed urethrocutaneous fistula vs 4/95 with mid-shaft hypospadias and 5/22 with proximal hypospadias. No difference was noted between the distal and mid-shaft groups. Significant differences were observed when comparing distal and mid-shaft groups with the proximal group; total complication rates were similar. Glans dehiscence and meatal stenosis rates were similar between Groups A and B, and among the hypospadias phenotypes. Conclusion Our modified procedure is simple to perform and yields excellent results in distal and mid-shaft hypospadias repair.

Here, the authors use tip-enhanced Raman spectroscopy for in-situ investigation of plasmon-induced [4+4]-cycloaddition polymerization on Au(111). They find that this occurs by a hot electron tunneling mechanism, while crosslinks form via a self-stimulating growth mechanism.

Abstract This paper is concerned with the second-order nonlinear Robin problem involving the first-order derivative: { u ″ + f ( t , u , u ′ ) = 0 , u ( 0 ) = u ′ ( 1 ) − α u ( 1 ) = 0 , $$ \textstyle\begin{cases} u''+f(t,u,u^{\prime })=0, \\ u(0)=u'(1)-\alpha u(1)=0,\end{cases} $$ where f ∈ C ( [ 0 , 1 ] × R + 2 , R + ) $f\in C([0,1]\times \mathbb{R}^{2}_{+},\mathbb{R}_{+})$ and α ∈ ] 0 , 1 [ $\alpha \in ]0,1[$ . Based on a priori estimates, we use fixed point index theory to establish some results on existence, multiplicity and uniqueness of positive solutions thereof, with the unique positive solution being the limit of of an iterative sequence. The results presented here generalize and extend the corresponding ones for nonlinearities independent of the first-order derivative.

2,4,6-trinitrotoluene (TNT) is a persistent pollutant; for removing it from environment, the biodegradation becomes an economical and environmentally friendly alternative. However, TNT is difficult to naturally mineralize due to the stability of benzene ring. Interestingly, the hydride metabolite (Hˉ-TNT) of TNT can produce dearomatized products by the biotransformation of old yellow enzyme (OYE) family, which is highly different with TNT. It is a promising strategy for the ring-opening degradation of TNT. Here, we explore the biotransformation difference of TNT and Hˉ-TNT by OYE family. The results show that the electron-withdrawing ability of nitro groups makes them obtain the majority of negative charges of Hˉ-TNT, which promotes the strong interaction between the substrate and key residues. It in turn promotes the formation of π-π stacking configuration between Hˉ-TNT and the flavin mononucleotide (FMN) cofactor, which is a precondition of the aromatic ring reduction. As a result, the aromatic ring reduction occupies an absolute advantage, while the nitro reduction is suppressed. The conclusions are in line with previous understanding and can explain experimental phenomena. This work can provide a valuable reference for the combined strategy of mineralizing TNT.

Amid the rapid development of nanosciences and nanotechnologies, plasmonics has emerged as an essential and fascinating discipline. Surface plasmons (SPs) lay solid physical foundations for plasmonics and have been broadly applied to ultrahigh-resolution spectroscopy, optical modulation, renewable energy, communication technology, etc. Sensitive optical characterizations for SPs, including far/near-field optics, spatial-resolved spectroscopy, and time-resolved behaviors of SPs, have prompted intense interest in diverse fields. In this Research Update, the ultrasensitive optical characterization for sub-radiant SPs is first introduced. Then, distinct characterization methods of nonlinear plasmonics, including plasmon-enhanced second harmonic generation and plasmon-enhanced sum frequency generation, are demonstrated in some classical nanostructures. Transient optical characterizations of SPs are also demonstrated in some well-defined nanostructures, enabling the deep realization of time-resolved behaviors. Finally, future prospects and efforts of optical characterization for SPs are proposed.

Abstract MXene has been found as a good host for lithium (Li) metal anodes because of its high specific surface area, lithiophilicity, good stability with lithium, and the in situ formed LiF protective layer. However, the formation of Li dendrites and dead Li is inevitable during long‐term cycle due to the lack of protection at the Li/electrolyte interface. Herein, a stable artificial solid electrolyte interface (SEI) is constructed on the MXene surface by using insulating g‐C3N4 layer to regulate homogeneous Li plating/stripping. The 2D/2D MXene/g‐C3N4 composite nanosheets can not only guarantee sufficient lithiophilic sites, but also protect the Li metal from continuous corrosion by electrolytes. Thus, the Ti3C2Tx/g‐C3N4 electrode enables conformal Li deposition, enhanced average Coulombic efficiency (CE) of 98.4%, and longer cycle lifespan over 400 cycles with an areal capacity of 1.0 mAh cm−2 at 0.5 mA cm−2. Full cells paired with LiFePO4 (LFP) cathode also achieve enhanced rate capacity and cycling stability with higher capacity retention of 85.5% after 320 cycles at 0.5C. The advantages of the 2D/2D lithiophilic layer/artificial SEI layer heterostructures provide important insights into the design strategies for high‐performance and stable Li metal batteries.

The Neoproterozoic is a very important stage in the global tectonic evolution, which experienced the amalgamation and break-up of the Rodinia. The Nanhua and Sinian strata in the Tarim Basin, which is one of the three major craton basins, have recorded a great deal of information about the tectonic attributes and plate dynamics of the basin in the Neoproterozoic. These are also the key strata for deep oil and gas exploration in the Tarim Craton Basin. Based on field investigations and studies of sedimentary characteristics, this paper studies the U-Pb dating of detrital zircons and provenance of sediments from the Sinian strata outcropped on the northwestern margin of the Tarim Basin. The age distribution of detrital zircons from the Sugetebrak Formation have five peaks in age of about 2 600, 2 300, 2 000-1 800, 790-730 and 620 Ma. The detrital zircons with peak ages of 2 600, 2 300 and 2 000-1 800 Ma are from the Neoarchean-Mesoproterozoic basement within the Tarim Craton, the detrital zircons with peak ages of 790-730 Ma may be derived from magmatic rocks formed by rifting during the late Neoproterozoic in the Tarim Basin, and the zircons with a peak age of 620 Ma were directly derived from magmatism at the time of formation deposition. These results suggest that the clastic material may have originated in the Tarim Basin itself. In view of the fault depression to depression structure on seismic profile, the rapidly filled turbidite sedimentary construction in the Nanhua strata, the transformation of Sinian strata from a clastic rock sequence to a marine carbonate sequence, and the magmatism during the sedimentary period of the Sinian Sugetebrak Formation, it is concluded that the northwestern margin of the Tarim Basin experienced the transition from fault-depression to rift subsidence during the Sinian.

To further enhance the hole-opening ability of the metal jet formed by the annular shaped charge on the armored steel target, a new annular shaped charge structure of a closed-cell W-shaped charge liner is designed based on a certain penetration depth. The impact of the length-diameter ratio of the charge, the inverted cone angle, and the cone angle of the liner on the opening diameter of the annular metal jet are studied through the orthogonal optimization of the annular shaped charge structures carried out by numerical simulation, which shows that the inverted cone angle and the cone angle of the liner are among the main factors that affect penetration depth and the opening diameter of the annular jet, respectively. According to this, an optimum annular charge structure considering both penetration depth and opening diameter is designed and tested by experiments. According to the results, the optimized annular jet records an opening diameter of 0.83 CD (Charge Diameter) when it penetrates the armored steel target with a thickness of 0.53 CD. The experimental results are consistent with the numerical simulation. The research results have certain practical engineering significance for guiding the design of the front-stage annular shaped charge structure of the multi-effect destructive warhead.

Active control of a stay cable through changing its tension is an effective way to lower the vibration amplitude. In this paper, active tendon control of a stay cable using a giant magnetostrictive actuator (GMA), which can generate axial deformation in a short period (normally less than 10 ms) under magnetic fields, is studied considering the time-delay. The bilinear controlled state equation of the small-sag cable is established by employing the Lagrange formulation. The linearization method for the bilinear controlled state equation is proposed and validated by numerical simulations. A GMA is designed and manufactured to actively control a stay cable model and the relationship between the output force and the input voltage is obtained by experiments. Based on the phase-shifting method, a multi-mode control algorithm with the time-delay compensation is proposed, and the time-delay compensation matrix based on the state feedback control algorithm is obtained. Based on a 1:20 scaled cable model, simulations and experiments are conducted to investigate the control performance of the proposed method under different external loads including the free vibration, harmonic excitation and random excitation. The results show that the tendon control of cable vibration by a GMA may be invalid and even amplify the vibration amplitude when the compensation of time-delay is not considered. Moreover, the excellent control performance can be achieved by using the proposed time-delay compensation method.

Antimicrobial peptides (AMPs) are thought to kill bacterial cells by permeabilizing their membranes. However, some antimicrobial peptides inhibit E. coli growth more efficiently in aerobic than in anaerobic conditions. In the attack of the human cathelicidin LL-37 on E. coli, real-time, single-cell fluorescence imaging reveals the timing of membrane permeabilization and the onset of oxidative stress. For cells growing aerobically, a CellROX Green assay indicates that LL-37 induces rapid formation of oxidative species after entry into the periplasm, but before permeabilization of the cytoplasmic membrane (CM). A cytoplasmic Amplex Red assay signals a subsequent burst of oxidative species, most likely hydrogen peroxide, shortly after permeabilization of the CM. These signals are much stronger in the presence of oxygen, a functional electron transport chain, and a large proton motive force (PMF). They are much weaker in cells growing anaerobically, by either fermentation or anaerobic respiration. In aerobic growth, the oxidative signals are attenuated in a cytochrome oxidase-bd deletion mutant, but not in a -bo3 deletion mutant, suggesting a specific effect of LL-37 on the electron transport chain. The AMPs melittin and LL-37 induce strong oxidative signals and exhibit O2-sensitive MICs, while the AMPs indolicidin and cecropin A do not. These results suggest that AMP activity in different tissues may be tuned according to the local oxygen level. This may be significant for control of opportunistic pathogens while enabling growth of commensal bacteria.

Plasmon-enhanced second-harmonic generation (PESHG) based on hybrid metal-dielectric nanostructures have extraordinary importance for developing efficient nanoscale nonlinear sources, which pave the way for new applications in photonic circuitry, quantum optics, and biosensors. However, the relatively high loss of excitation energies and the low spatial overlapping between the locally enhanced electromagnetic field and nonlinear materials still limit the promotion of nonlinear conversion performances in such hybrid systems. Here, we design and fabricate an array of silver nanoparticle-ZnO (AgNP-ZnO) nanocavities to serve as an efficient PESHG platform. The geometry of AgNP-ZnO nanocavity arrays provides a way to flexibly modulate hot spots in three-dimensional space, and to achieve a good mutual overlap of hot spots and ZnO material layers for realizing efficient SH photon generation originating from ZnO nanocavities. Compared to bare ZnO nanocavity arrays, the resulting hybrid AgNP-ZnO design of nanocavities reaches the maximum PESHG enhancement by a factor of approximately 31. Validated by simulations, we can further interpret the relative contribution of fundamental and harmonic modes to Ag-NP dependent PESHG performances, and reveal that the enhancement stems from the co-cooperation effect of plasmon-resonant enhancements both for fundamental and harmonic frequencies. Our findings offer a previously unreported method for designing efficient PESHG systems and pave a way for further understanding of a surface plasmon-coupled second-order emission mechanism for the enhancement of hybrid systems.

In this article we study the existence and multiplicity of positive solutions for the system of second-order boundary value problems involving first order derivatives $$displaylines{ -u''=f(t, u, u', v, v'),cr -v''=g(t, u, u', v, v'),cr u(0)=u'(1)=0,quad v(0)=v'(1)=0. }$$ Here $f,gin C([0,1]imes mathbb{R}_+^{4}, mathbb{R}_+)(mathbb{R}_+:=[0,infty))$. We use fixed point index theory to establish our main results based on a priori estimates achieved by utilizing Jensen's integral inequality for concave functions and $mathbb{R}_+^2$-monotone matrices.

In this article we study the existence of positive solutions for the system of higher order boundary-value problems involving all derivatives of odd orders $$displaylines{ (-1)^mw^{(2m)} =f(t, w, w',-w''',dots, (-1)^{m-1}w^{(2m-1)}, z, z',-z''',dots, (-1)^{n-1}z^{(2n-1)}), cr (-1)^nz^{(2n)} =g(t, w, w',-w''',dots, (-1)^{m-1}w^{(2m-1)}, z, z',-z''',dots, (-1)^{n-1}z^{(2n-1)}), cr w^{(2i)}(0)=w^{(2i+1)}(1)=0quad (i=0,1,dots, m-1),cr z^{(2j)}(0)=z^{(2j+1)}(1)=0quad (j=0,1,dots, n-1). } $$ Here $f,gin C([0,1]imesmathbb{R}_+^{m+n+2},mathbb{R}_+)$ $(mathbb{R}_+:=[0,+infty))$. Our hypotheses imposed on the nonlinearities $f$ and $g$ are formulated in terms of two linear functions $h_1(x)$ and $h_2(y)$. We use fixed point index theory to establish our main results based on a priori estimates of positive solutions achieved by utilizing nonnegative matrices.

In this paper, we investigate the existence, multiplicity and uniqueness of positive solutions for the following system of $n$th-order nonlinear boundary value problems \[\begin{cases} u^{(n)}(t)+f(t,u(t),v(t))=0,0

This article concerns the existence and multiplicity of positive solutions for the singular Sturm-Liouville boundary value problem $$displaylines{ (p(t)u'(t))'+h(t)f(t,u(t))=0,quad 0

In this article, we show the existence of at least three positive solutions for the system of singular generalized Lidstone boundary value problems $displaylines{ (-1)^m x^{(2m)}=a(t)f_1(t,x,-x'',dots,(-1)^{m-1}x^{(2m-2)},y,-y'',cr dots,(-1)^{n-1}y^{(2n-2)}), cr (-1)^n y^{(2n)}=b(t)f_2(t,x,-x'',dots,(-1)^{m-1}x^{(2m-2)},y,-y'',cr dots,(-1)^{n-1}y^{(2n-2)}), cr a_1 x^{(2i)}(0)-b_1 x^{(2i+1)}(0)=c_1x^{(2i)}(1)+d_1 x^{(2i+1)}(1)=0,cr a_2y^{(2j)}(0)-b_2y^{(2j+1)}(0)=c_2y^{(2j)}(1)+d_2y^{(2j+1)}(1)=0. }$$ The proofs of our main results are based on the Leggett-Williams fixed point theorem. Also, we give an example to illustrate our results.