The Chinese Government recently approved guidelines for reform of the health-care system and published an action plan of targets for reform in 2009-11.1,2 Estimates suggest that governmental ...investment (both central and local) of CNY850 billion (about US$124 billion) will be injected into the health-care system in the coming 3 years, doubling the average annual governmental expenditure compared with 2008. Since China adopted its "Reform and opening up" policy in 1978,3 the medical care system and health of residents has developed rapidly. ... the medical care and public health service system will be improved at grassroots level.
The formation of C‐heteroatom bonds represents an important type of bond‐forming reaction in organic synthesis and often provides a fast and efficient access to privileged structures found in ...pharmaceuticals, agrochemical and materials. In contrast to conventional Pd‐ or Cu‐catalyzed C‐heteroatom cross‐couplings under high‐temperature conditions, recent advances in homo‐ and heterogeneous Ni‐catalyzed C‐heteroatom formations under mild conditions are particularly attractive from the standpoint of sustainability and practicability. The generation of NiIII and excited NiII intermediates facilitate the reductive elimination step to achieve mild cross‐couplings. This review provides an overview of the state‐of‐the‐art approaches for mild C‐heteroatom bond formations and highlights the developments in photoredox and nickel dual catalysis involving SET and energy transfer processes; photoexcited nickel catalysis; electro and nickel dual catalysis; heterogeneous photoredox and nickel dual catalysis involving graphitic carbon nitride (mpg‐CN), metal organic frameworks (MOFs) or semiconductor quantum dots (QDs); as well as more conventional zinc and nickel dual catalyzed reactions.
The generation of NiIII and excited NiII intermediates facilitates the reductive elimination step leading to the mild cross‐couplings. This review provides an overview of the state‐of‐the‐art approaches for mild C‐heteroatom bond formations via homo‐ and heterogeneous photoredox and nickel dual catalysis, electro‐ and nickel dual catalysis, as well as conventional zinc and nickel dual catalysis.
Cascade reactions that produce multiple chemical bonds in one synthetic operation are important in the efficient construction of complex molecules. In addition, photoredox and nickel dual catalysis ...opens a new and powerful avenue for transition-metal-catalyzed cross-coupling reactions. By combining these two concepts, photoredox and nickel dual-catalyzed cascade reactions have been recently established, and they provide an efficient and mild method for accessing a series of valuable organic compounds.
Cascade reactions that produce multiple chemical bonds in one synthetic operation are important in the efficient construction of complex molecules.
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•Ultrafast microwave-assisted ChCl: LA DES pretreatment was developed.•The pretreatment only took 45 s but was highly effective for biomass fractionation.•Lignin and xylan were ...substantially removed while most of cellulose was retained.•The pretreatment increased the cellulose digestibility by 2–5 folds.•Lignin was recovered with relatively high purity (85–87%).
Deep eutectic solvents (DESs) have received increasing attention in recent years as designer solvents for bioprocessing. In this study, ultrafast microwave-assisted DES pretreatment was developed for lignocellulose fractionation. The pretreatment was conducted for 45 s with microwave irradiation at 800 W using a DES composed of choline chloride and lactic acid (ChCl: LA). The results indicated that such pretreatment was highly effective in removing lignin and xylan while retaining most of cellulose in the pretreated solids. The ultrafast fractionation increased the cellulose digestibility by 2–5 folds. Switchgrass gave a similar glucose yield to corn stover but experienced less cellulose loss during the pretreatment. Miscanthus was also substantially fractionated but showed lower digestibility than switchgrass and corn stover. Lignin was readily recoverable with relatively high purity from all the pretreatment liquor. Our study demonstrated an innovative ultrafast pretreatment process with superior effectiveness for biomass fractionation and cellulose digestibility improvement as well as lignin extraction.
Rumination is strongly and consistently correlated with depression. Although multiple studies have explored the neural correlates of rumination, findings have been inconsistent and the mechanisms ...underlying rumination remain elusive. Functional brain imaging studies have identified areas in the default mode network (DMN) that appear to be critically involved in ruminative processes. However, a meta-analysis to synthesize the findings of brain regions underlying rumination is currently lacking. Here, we conducted a meta-analysis consisting of experimental tasks that investigate rumination by using Signed Differential Mapping of 14 fMRI studies comprising 286 healthy participants. Furthermore, rather than treat the DMN as a unitary network, we examined the contribution of three DMN subsystems to rumination. Results confirm the suspected association between rumination and DMN activation, specifically implicating the DMN core regions and the dorsal medial prefrontal cortex subsystem. Based on these findings, we suggest a hypothesis of how DMN regions support rumination and present the implications of this model for treating major depressive disorder characterized by rumination.
•Rumination is strongly and consistently correlated with depression.•Meta-analyze the findings of brain regions regarding to rumination.•Specifically examined the contribution of three DMN subsystems to rumination.•Rumination is specifically correlated with the DMN core regions and the dorsal medial prefrontal cortex subsystem.
The carbon‐carbon (C—C) σ‐bonds construct the fundamental frameworks of organic molecules. The direct functionalization of C—C bonds represents one of the most efficient and step‐economical ...transformations in synthetic chemistry. The past few decades have witnessed the fast development of transition‐metal mediated C—C bond activation. In contrast, the radical‐promoted C—C bond cleavage has received relatively less attention. As the occurrence of ring strain significantly facilitates the fission of cyclic C—C bonds via radical approaches, the strain relief‐driven C—C bond activation mostly relies on the three‐ and four‐membered rings. The C—C activation of non‐strained molecules such as medium‐ or large‐sized rings and linear alkanes remains challenging. In this review, we will focus on the recent advances in radical‐mediated C—C bond activation of non‐strained molecules. Herein, the alkoxy‐ and iminyl‐radical triggered scission of non‐strained C—C bonds and C—C cleavage via the strategy of remote functional group migration is summarized.
The recent advances in radical‐mediated C—C bond activation of non‐strained molecules are summarized in this review. These transformations are mainly accomplished during the past three years, thus representing an emerging topic in organic chemistry. The alkoxy‐ and iminyl‐radical triggered cleavage of non‐strained C—C bonds and the C—C activation via the strategy of remote functional group migration are discussed in details.
Cycloalkanols prove to be privileged precursors for the synthesis of distally substituted alkyl ketones and polycyclic aromatic hydrocarbons (PAHs) by virtue of cleavage of their cyclic C−C bonds. ...Direct functionalization of cyclobutanols to build up other chemical bonds (e. g., C−F, C−Cl, C−Br, C−N, C−S, C−Se, C−C, etc.) has been achieved by using the ring‐opening strategy. Mechanistically, the C−C cleavage of cyclobutanols can be involved in two pathways: (a) transition‐metal catalyzed β‐carbon elimination; (b) radical‐mediated ‘radical clock’‐type ring opening. The recent advances of our group for the ring‐opening functionalization of tertiary cycloalkanols are described in this account.
C−C σ‐bond cleavage: cycloalkanols prove to be privileged precursors for the synthesis of distally substituted alkyl ketones and polycyclic aromatic hydrocarbons (PAHs) by virtue of cleavage of their cyclic C−C bonds. The recent advances in the ring‐opening functionalization of tertiary cycloalkanols are summarized in this account.
An efficient photoredox/nickel catalyzed sulfonylation reaction of aryl, heteroaryl, and vinyl halides has been achieved for the first time. This newly developed sulfonylation protocol provides a ...versatile method for the synthesis of diverse aromatic sulfones at room temperature and shows excellent functional group tolerance. The electrophilic coupling partners are not limited to aryl, heteroaryl, and vinyl bromides and iodides, but also includes less reactive aryl chlorides as suitable substrates for this transformation.
Isn't it Ir(o)Ni(c)? An efficient photoredox/nickel catalyzed sulfonylation reacticon of aryl, heteroaryl, and vinyl halides has been achieved for the first time. The protocol provides a versatile method for the synthesis of diverse aromatic sulfones at room temperature and shows excellent functional group tolerance. Moreover, the electrophilic coupling partners also include the less reactive aryl chlorides. Ts=4‐toluenesulfonyl.
Radical‐mediated difunctionalization of alkenes is a powerful tactic for olefin utilization. However, the transformation of unactivated alkenes still remains a formidable challenge. Now a ...conceptually new docking–migration strategy is presented for the difunctionalization of alkenes with photoredox catalysis. Both activated and unactivated alkenes are suitable substrates. A vast array of functional groups are compatible with the mild reaction conditions. Heteroaryl and difluoromethyl are concomitantly incorporated into alkenes, leading to synthetically valuable products that are readily converted into a variety of fluorine‐containing molecules. The protocol provides a kinetic control of stereoselectivity for cycloalkenes to generate the unusual cis‐products, and offers an efficient approach for the late‐stage functionalization of complex natural products and drug molecules. A portfolio of dual‐function reagents are prepared for the elusive radical difunctionalization of alkenes.
All aboard: A conceptually new docking–migration strategy for the difunctionalization of alkenes under visible‐light photoredox catalysis is disclosed. Both activated and unactivated alkenes are suitable substrates. A vast array of functional groups are compatible with the mild reaction conditions.
Sustainability is crucially important in the textiles and apparel (TA) supply chains. In this paper, we evaluate the impact of clean technology adoption and environmental taxes on the TA supply ...chains. First, we consider a monopoly case, where a two-echelon supply chain consists of one buyer and one manufacturer. We find that raising the environmental tax rate motivates the manufacturer to invest in green technologies. We then extend our model to examine the duopoly case. We find that in the duopoly case, if the buyer's market share is sufficiently small (large), the optimal greenness level for this buyer's product decreases (increases) in the environmental tax rate; whereas if the two products market shares are relatively equal, the optimal greenness levels for both products buyers increase in the environmental tax rate. The existence of the spillover effect reduces the cost and improves the product greenness. Consumer welfare can be improved if the efficiency of green technology adoption and the coefficient of greenness level on market demand are sufficiently high. This result implies that if the government cares about consumers, the manufacturer should be encouraged to enhance the cost reduction ability in terms of green technology, and consumer education about sustainability consciousness should be enhanced.
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