Simultaneous 2-photon and 3-photon excitation with a red fluorescent protein-cyanine dye probe pair in the 1700-nm excitation window for deep neurovascular imaging.

imaging of the neurovascular network is considered to be one of the most powerful approaches for understanding brain functionality. Nevertheless, simultaneously imaging the biological neural network and blood vessels in deep brain layers in a non-invasive manner remains to a major challenge due to the lack of appropriate labeling fluorescence probe pairs. Herein, we proposed a 2-photon and 3-photon fluorescence probe pair for neurovascular imaging.

Light-Initiated Four-Step Domino-Multicomponent Synthesis of Functionalized Alkylidenecyclobutanes.

A four-step domino-multicomponent reaction (domino-MCR) is described for the synthesis of functionalized -alkylidenecyclobutanes from 4-hydroxy-2-methylcyclopent-2-enone derivatives and three other simple reagents. The domino-MCR is accomplished in a single protocol, comprising a tandem photochemical [2 + 2]-cycloaddition/Norrish-I/γ-H transfer reaction followed by an acetal protection and an allylic substitution reaction. In parallel, a consecutive process has been established with distinct photochemical and nonradiative sequences.

Oxygen Concentration Effect in Photosensitized Generation of O from Normoxia to Hypoxia.

Photodynamic therapy (PDT) has gained widespread acceptance as a clinical cancer treatment modality and has been attracting intensive attention on developing novel PDT strategies. However, the hypoxic environment in tumors is considered as a significant challenge for efficient type II PDT, based on the inference of the highly oxygen-concentration-related O generation. Contrary to this conventional understanding, our research demonstrates oxygen concentration independence in the photosensitized generation of O, as evidenced through steady-state and transient spectroscopy for chlorin e6 and methylene blue from normoxic to hypoxic conditions.

A mitochondrion-targeted cyanine agent for NIR-II fluorescence-guided surgery combined with intraoperative photothermal therapy to reduce prostate cancer recurrence.

Poorly identified tumor boundaries and nontargeted therapies lead to the high recurrence rates and poor quality of life of prostate cancer patients. Near-infrared-II (NIR-II) fluorescence imaging provides certain advantages, including high resolution and the sensitive detection of tumor boundaries. Herein, a cyanine agent (CY7-4) with significantly greater tumor affinity and blood circulation time than indocyanine green was screened.

Reactive Matrices for MALDI-MS of Cholesterol.

Cholesterol is a critical molecule whose dysregulation in certain brain regions is related to multiple neurological disorders. It is of pathological importance to map the distribution of cholesterol in brain. Matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) has been widely used in the molecular imaging of metabolites at a high spatial resolution.

Single-dye NIR-II chemiluminescence system for HO imaging.

An efficient single-dye NIR-II CL system was proposed for the first time with the longest emission peak around 1000 nm. Biocompatible CL nanoparticles were developed and a surprising CL intensity enhancement was found in the presence of the BASZn nanoenzyme by about three orders of magnitude. Such an NIR-II CL system was demonstrated for glucose sensing, tumor therapy and HO imaging.

A fast forward algorithm of azimuthal gamma imaging logging while drilling.

Logging while drilling (LWD) technology can evaluate the formation interface and stratigraphic properties around the borehole in real time, so as to adjust the drilling trajectory and effectively improve the reservoir encounter rate. Fast forward algorithm can be used with LWD, by comparing the fast forward results with the actual gamma LWD results, it can distinguish the formation interface more accurately. Fast forward algorithm also can provide a theoretical basis for geosteering and azimuthal gamma logging interpretation.

BSA-Coated Gold Nanorods for NIR-II Photothermal Therapy.

The second near infrared window is considered to be the optimal optical window for medical imaging and therapy as its capability of deep tissue penetration. The preparation of the gold nanorods with long wavelength absorption and low cytotoxicity is still a challenge. A series gold nanorods with large aspect ratio have been synthesized.

Stereocontrolled Preparation of Diversely Trifunctionalized Cyclobutanes.

The expedient and stereoselective syntheses of small libraries of trifunctionalized cyclobutane scaffolds bearing an acid, an amine, and a third functional group are described. Starting from a single precursor, the readily available protected derivative of -2-amino-3-hydroxycyclobutane-1-carboxylic acid, stereoisomers are obtained following an S2-type reaction, while stereoisomers are obtained using the same strategy preceded by a C1 epimerization reaction.

Preparation of Cyclobutene Acetals and Tricyclic Oxetanes through Photochemical Tandem and Cascade Reactions.

We describe a photochemical reaction using two starting materials, a cyclopent-2-enone and an alkene, which are transformed in a controlled manner via the initial [2+2]-photocycloaddition adducts into cyclobutene aldehydes (conveniently trapped as stable acetals) or unprecedented angular tricyclic 4:4:4 oxetane-containing skeletons. These compounds are formed through tandem or triple cascade photochemical reaction processes, respectively. Small libraries of each compound class were prepared, thus suggesting that this photochemistry approach opens new opportunities for synthesis design and for widening molecular diversity.

A Photochemical Route to 3- and 4-Hydroxy Derivatives of 2-Aminocyclobutane-1-carboxylic Acid with an all-cis Geometry.

Short gram-scale syntheses of both enantiomers of 2-amino-3-hydroxycyclobutane-1-carboxylic acid and of 2-amino-4-hydroxycyclobutanecarboxylic acid with an all-cis geometry are described. The sequences feature highly endo-selective [2 + 2]-photocycloaddition reactions followed by fully regioselective ring opening/Hofmann rearrangement/nitrogen protection, in a consecutive or one-pot protocol, followed by efficient resolution using a chiral oxazolidinone.

General and chemoselective bisphosphonylation of secondary and tertiary amides.

With Tf2O as the activation reagent, a mild and general method has been developed for the bisphosphonylation of both secondary and tertiary amides. The protocol is highly efficient and chemoselective, and it tolerates a number of sensitive functional groups such as cyano, ester, and aldehyde groups.

Enantioselective total synthesis of (+)-methoxystemofoline and (+)-isomethoxystemofoline.

The first enantioselective total synthesis of (+)-methoxystemofoline (2) and (+)-isomethoxystemofoline (3) has been reported. The synthesis employed the halide-assisted bromotropanonation method that we developed recently to construct the core structure, and Overman's strategy for the implementation of the butenolide moiety. Through this work, the structure of methoxystemofoline was revised as with an E-alkene, and its absolute configuration was established.

Versatile construction of functionalized tropane ring systems based on lactam activation: enantioselective synthesis of (+)-pervilleine B.

The halo-assisted intramolecular addition of silyl enol ethers with in situ activated lactams yielded (hydroxylated) 1-halo-8-azabicyclo[3,2,1]octane and 1-halo-9-azabicyclo[3,3,1]nonane ring systems, which provided an easy enantioselective access to 6β-silyloxytropane-3-one, 3α,6β-dihydroxytropane, and pervilleine B. The absolute configuration of the natural (-)-pervilleine B was determined to be 1R,3R,5S,6R.

Human influence on the population decline and loss of genetic diversity in a small and isolated population of Sichuan snub-nosed monkeys (Rhinopithecus roxellana).

Human activities have caused worldwide loss and fragmentation of natural habitats, resulting in the decline and isolation of wild populations, consequently increasing their risks of extinctions. We investigated the genetic consequences of anthropogenic effects on the Sichuan snub-nosed monkeys (Rhinopithecus roxellana) in the Shennongjia Nature Reserve (SNR), which is a small and isolated distribution of R. roxellana in China and would continue to be threatened by habitat degradation and loss, using extensive sampling and 16 microsatellite loci.

Binding and internalization of glucuronoxylomannan, the major capsular polysaccharide of Cryptococcus neoformans, by murine peritoneal macrophages.

Glucuronoxylomannan (GXM), the major component of the capsular polysaccharide of Cryptococcus neoformans, is essential to virulence of the yeast. Previous studies found that the interaction between GXM and phagocytic cells has biological consequences that may contribute to the pathogenesis of cryptococcosis. We found that GXM binds to and is taken up by murine peritoneal macrophages.

cAMP elevators inhibit LPS-induced IL-12 p40 expression by interfering with phosphorylation of p38 MAPK in murine peritoneal macrophages.

cAMP mediated signaling may play a suppressive role in immune response. We previously found that the cAMP-elevators (CTx and 8-Br-cAMP) inhibited IL-12, IL-la, IL-6 gene expression, but increased the transcriptional levels of IL-10 and IL-1Ra in LPS-treated murine peritoneal macrophages. The present study examined a possible molecular mechanism involved in cAMP elevators-induced inhibition of IL-12 p40 expression in response to LPS.

In vivo canine coronary artery laser irradiation: photodynamic therapy using dihematoporphyrin ether and 632 nm laser. A safety and dose-response relationship study.

This study examined the safety and dose-response relationships of 632-nm laser irradiation of photosensitized normal coronary arteries in 27 dogs. Fifteen received 2.5 mg/kg dihematoporphyrin ether (DHE), seven received no sensitizer, and five had coronary instrumentation but no laser (sham laser procedures) at nine coronary sites--four sensitized, five non-sensitized.