Welding Characteristics of Medium Titanium Plates with Autogenous Laser Welding and Narrow-Gap Laser Filling Welding Modes.

Titanium and titanium alloys with a medium thickness of 5 to 12 mm are widely used for ocean platforms, military equipment and in other fields because of their light weight, appropriate strength and corrosion resistance. In this study, autogenous laser welding and narrow-gap laser welding processes were researched and compared, and the welding characteristics, weld microstructure and joint strength were analyzed. The results showed that autogenous laser welding had higher efficiency, narrower weld width and higher microstructure uniformity.

Pressure-induced novel ZrN semiconductor materials with high dielectric constants: a first-principles study.

In addition to ZrN and ZrN compounds, zirconium nitrides with a rich family of phases always exhibit metal phases. By employing an evolutionary algorithm approach and first-principles calculations, we predicted seven novel semiconductor phases for the ZrN system at 0-150 GPa. Through calculating phonon dispersions, we identified four dynamically stable semiconductor structures under ambient pressure, namely, α-1̄, β-1̄, γ-1̄, and β-1 (with bandgaps of 1.

Impairments in endogenous AMPA receptor dynamics correlates with learning deficits in Alzheimer's disease model mice.

AMPA receptors (AMPARs) play a critical role in synaptic plasticity and learning and memory, and dysfunction or dysregulation of AMPARs could lead to various neurological and psychiatric disorders, such as Alzheimer's disease (AD). However, the dynamics and/or longitudinal changes of AMPARs in vivo during AD pathogenesis remain elusive. Here, employing 5xFAD SEP-GluA1 KI mice, we investigated endogenous AMPA receptor dynamics in a whisker deflection-associated Go/No-go learning paradigm.

Pathological hemodynamic changes and leukocyte transmigration disrupt the blood-spinal cord barrier after spinal cord injury.

Background: Blood-spinal cord barrier (BSCB) disruption is a key event after spinal cord injury (SCI), which permits unfavorable blood-derived substances to enter the neural tissue and exacerbates secondary injury. However, limited mechanical impact is usually followed by a large-scale BSCB disruption in SCI. How the BSCB disruption is propagated along the spinal cord in the acute period of SCI remains unclear.

The neurovascular unit in healthy and injured spinal cord.

The neurovascular unit (NVU) reflects the close temporal and spatial link between neurons and blood vessels. However, the understanding of the NVU in the spinal cord is far from clear and largely based on generalized knowledge obtained from the brain. Herein, we review the present knowledge of the NVU and highlight candidate approaches to investigate the NVU, particularly focusing on the spinal cord.

Moderate systemic therapeutic hypothermia is insufficient to protect blood-spinal cord barrier in spinal cord injury.

Blood-spinal cord barrier (BSCB) disruption is a pivotal event in spinal cord injury (SCI) that aggravates secondary injury but has no specific treatment. Previous reports have shown that systemic therapeutic hypothermia (TH) can protect the blood-brain barrier after brain injury. To verify whether a similar effect exists on the BSCB after SCI, moderate systemic TH at 32°C was induced for 4 h on the mice with contusion-SCI.

5-aminolevulinic acid-mediated photodynamic therapy (ALA-PDT) for acneform rash induced by erlotinib: A case report.

Erlotinib is an anticancer drug approved for the treatment of non-small cell lung cancer. It inhibits growth and proliferation of tumor cells by targeting epidermal growth factor receptor (EGFR). Dermatological toxicities are common side effects associated with EGFR inhibition.

Terminal Trifluoromethylation of Ketones via Selective C-C Cleavage of Cycloalkanols Enabled by Hypervalent Iodine Reagents.

We report the first terminal trifluoromethylation at aryl and alkyl ketones' γ, δ, ε, or more remote sites via the selective C-C bond cleavage of cycloalkanols. The noncovalent interactions between alcohols and hypervalent iodines(III) reagents were disclosed to activate both alcohols and the Togni I reagent in the dual photoredox/copper catalysis for the transformation. This reaction was scalable to the gram-scale synthesis, applicable to the structurally complex steroid trifluoromethylation, and extendable to the pentafluoroethylation.

Safinamide prevents lipopolysaccharide (LPS)-induced inflammation in macrophages by suppressing TLR4/NF-κB signaling.

Inflammation is a basal host defense response that eliminates the causes and consequences of infection and tissue injury. Macrophages are the primary immune cells involved in the inflammatory response. When activated by LPS, macrophages release various pro-inflammatory cytokines, chemokines, inflammatory mediators, and MMPs.

Microstructure and Mechanical Properties of Al/Steel Butt Joint by Hybrid CMT Welding with External Axial Magnetic Field.

The 6061 aluminum alloy and 304 stainless steel were welded by hybrid cold metal transfer (CMT) welding with external axial magnetic field. The effects of magnetic intensity and frequency on joint microstructure and mechanical properties were studied. It was found that the magnetic field can promote the spreading of aluminum weld metal on the steel surface and thus increase the bonding area of Al/steel butt joint.

Weld Formation Mechanism and Microstructural Evolution of TC4/304 Stainless Steel Joint with Cu-Based Filler Wire and Preheating.

Ti-Fe intermetallic compounds were effectively suppressed with Cu-based filler wire and weld formation was greatly improved with the preheating of substrates when joining TC4 titanium alloy and 304 stainless steel. A Ti/Cu transition zone consisting of complex TiCu, TiCu, TiFe, and TiFe phases was formed between Cu-weld/TC4 interface, while Cu-weld/304ss interface was mainly composed of α-Fe and ε-Cu solid solution. At lower heat input, the undercut defect in back surface had potential to cause crack initiation and joint fracture.

Acyl Radical Smiles Rearrangement To Construct Hydroxybenzophenones by Photoredox Catalysis.

The first visible-light-induced acyl radical Smiles rearrangement to transform biaryl ethers to hydroxybenzophenones under mild and metal-free conditions is reported. Using the dual catalysis of hypervalent iodine(III) reagents and organophotocatalysts, ketoacids readily generate acyl radicals and undergo 1,5- ipso addition. This method can construct electron-deficient and electron-rich hydroxybenzophenones with excellent chemoselectivity and on gram scale.

Selective P-C(sp ) Bond Cleavage and Radical Alkynylation of α-Phosphorus Alcohols by Photoredox Catalysis.

Herein the first P-C(sp ) bond cleavage and radical alkynylation of α-phosphorus alcohols to construct phosphonoalkynes is reported. The phosphorus radical is generated upon P-C bond cleavage reaction via the alkoxyl radical through photoredox catalysis with cyclic iodine(III) reagents. Various arylphosphinoyl-, alkylphosphinoyl-, phosphonate-, and phosphonic amide alcohols serve as radical phosphorus precursors to construct phosphonoalkynes for the first time.

PtCl-catalyzed skeleton rearrangement-cyclization of tertiary indolyl-3-alkynols.

An unexpected PtCl-catalyzed cyclization reaction of tertiary indol-2-yl-3-alkynols occurred smoothly in toluene to form various poly-substituted carbazole derivatives efficiently. A possible mechanism involving the formation of a spiro-tricyclic intermediate via indole C-2 attack, highly selective ring expansion and then 1,2-migration has been proposed for the formation of carbazoles.

Asymmetric Construction of Six-Membered Rings by Cyclization of Allenes with Dinuclear Gold Catalysis.

A simple and efficient method for the synthesis of 1,4-dihydroarenes by gold-catalyzed 6-endo cyclization of benzylic allenes has been developed. Furthermore, asymmetric hydroarylation of enantioenriched allenes has been realized to offer a practical and convergent approach to aromatic ring-fused six-membered cycles containing a chiral stereocenter such as 1,4-dihydronaphthalenes, 1,4-dihydrodibenzo[b,d]thiophenes, and 4,7-dihydrobenzo[b]thiophenes by applying dinuclear [(dppm)Au2 Cl2 ] [dppm=methylenebis(diphenylphosphane)] combined with AgOTf as the catalyst to ensure the high efficiency of chirality transfer. ESI-MS has been applied to characterize some of the key reactive dinuclear gold intermediates successfully.

[Levels of TNF-α, IL-6 and IL-10 in bronchoalveolar lavage fluid in children with Mycoplasma pneumoniae pneumonia].

Objective: To study the levels and roles of cytokines TNF-α, IL-6 and IL-10 in bronchoalveolar lavage fluid (BALF) in children with Mycoplasma pneumoniae pneumonia (MPP).

Methods: The levels of TNF-α, IL-6 and IL-10 in BALF were measured using ELISA in children with MPP at acute stage (n=45) and at remission stage (n=30). Twenty children without lung lesions severed as the control group.