Nickel-Catalyzed Carbonylative Negishi Cross-Coupling of Unactivated Secondary Alkyl Electrophiles with 1 atm CO Gas.

We describe a nickel-catalyzed carbonylative cross-coupling of unactivated secondary alkyl electrophiles with the organozinc reagent at atmospheric CO gas, thus allowing the expedient construction of unsymmetric dialkyl ketones with broad functional group tolerance. The leverage of a newly developed NN2-pincer type ligand enables the chemoselective three-component carbonylation by overcoming the competing Negishi coupling, the undesired ß-hydride elimination, and dehalogenation of alkyl iodides side pathways. Both alkyl iodides and alkyl tosylates are compatible in the single electron transfer involved mechanism.

Palladium-Catalyzed Enantioselective Multicomponent Cross-Coupling of Trisubstituted Olefins.

The development of a catalytic method for stereogenic carbon center formation holds immense significance in organic synthesis. Transition-metal-catalyzed cross-coupling reaction has been regarded as a straightforward and efficient tool for stereoselectively forging C-C bond. Nevertheless, the creation of acyclic all-carbon quaternary-containing vicinal stereocenters remains notoriously challenging within the domain of cross-coupling chemistry despite their prominence in various bioactive small molecules. Herein, we describe a palladium-catalyzed asymmetric multicomponent cross-coupling of trisubstituted alkene with aryl diazonium salts and arylboronic acids to realize the formation of tertiary-quaternary carbon centers with high regio-, distereo-, and enantioselectivity. Specifically, the precise manipulation of the stereoconfiguration of trisubstituted alkenes enables the divergent stereoselective cross-coupling reaction, thus allowing for the facile construction of all four enantiomers. Harnessing the ligand-swap strategy involving a chiral bisoxazoline and an achiral fumarate individually accelerates the enantioselective migratory insertion and reductive elimination step in the cross-coupling process, as supported by density functional theory (DFT) calculations, thus obviating the requirement for a neighboring directing group within the internal olefin skeleton.

Buoyancy-Driven Dissolution Instability in a Horizontal Hele-Shaw Cell.

The dissolution of minerals within rock fractures is fundamental to many geological processes. Previous research on fracture dissolution has highlighted the significant role of buoyancy-driven convection leading to dissolution instability. Yet, the pore-scale mechanisms underlying this instability are poorly understood primarily due to the challenges in experimentally determining flow velocity and concentration fields. Here, we integrate pore-scale simulations with theoretical analysis to delve into the dissolution instability prompted by buoyancy-driven convection in a radial horizontal geometry. Initially, we develop a pore-scale modeling approach incorporating gravitational effects, subsequently validating it through experiments. We then employ pore-scale numerical simulations to elucidate the 3D intricacies of flow-dissolution dynamics. Our findings reveal that a simple criterion can delineate the condition for the onset of buoyancy-driven dissolution instability. If the characteristic length falls below a critical threshold, dissolution remains stable. Conversely, exceeding this threshold leads to two distinct regimes: the unstable regime of the confined domain affected by the initial aperture and the unstable regime of the semi-infinite domain independent of the initial aperture where the instability is no longer influenced by the lower boundary. We demonstrate that the pore-scale mechanism for this instability is due to the concentration boundary layer attaining a gravitationally unstable critical thickness. Through theoretical analysis of this layer and the time scales of diffusion and advection, we establish a theoretical model to predict where the dissolution instability occurs. This model aligns closely with our numerical simulations and experimental data across diverse conditions. Our work improves the understanding of buoyancy-driven dissolution instability in radial horizontal geometry. It is also of practical significance in understanding cavity formation in karst hydrology and preventing leaks in geological CO2 storage.

Enhanced CO2 Capture through SAPO-34 Impregnated with Ionic Liquid.

The concurrent utilization of an adsorbent and absorbent for carbon dioxide (CO2) adsorption with synergistic effects presents a promising technique for CO2 capture. Here, 1-butyl-3-methylimidazole acetate ([Bmim][Ac]), with a high affinity for CO2, and the molecular sieve SAPO-34 were selected. The impregnation method was used to composite the hybrid samples of [Bmim][Ac]/SAPO-34, and the pore structure and surface property of prepared samples were characterized. The quantity and kinetics of the sorbed CO2 for loaded samples were measured using thermogravimetric analysis. The study revealed that SAPO-34 could retain its pristine structure after [Bmim][Ac] loading. The CO2 uptake of the loaded sample was 1.879 mmol g-1 at 303 K and 1 bar, exhibiting a 20.6% rise compared to that of the pristine SAPO-34 recording 1.558 mmol g-1. The CO2 uptake kinetics of the loaded samples were also accelerated, and the apparent mass transfer resistance for CO2 sorption was significantly reduced by 11.2% compared with that of the pure [Bmim][Ac]. The differential scanning calorimetry method revealed that the loaded sample had a lower CO2 desorption heat than that of the pure [Bmim][Ac], and the CO2 desorption heat of the loaded samples was between 30.6 and 40.8 kJ mol-1. The samples exhibited good cyclic stability. This material displays great potential for CO2 capture applications, facilitating the reduction of greenhouse gas emissions.

Comprehensive Mechanistic Analysis of Palladium- and Nickel-Catalyzed α,ß-Dehydrogenation of Carbonyls via Organozinc Intermediates.

Introducing degrees of unsaturation into small molecules is a central transformation in organic synthesis. A strategically useful category of this reaction type is the conversion of alkanes into alkenes for substrates with an adjacent electron-withdrawing group. An efficient strategy for this conversion has been deprotonation to form a stabilized organozinc intermediate that can be subjected to α,ß-dehydrogenation through palladium or nickel catalysis. This general reactivity blueprint presents a window to uncover and understand the reactivity of Pd- and Ni-enolates. Within this context, it was determined that ß-hydride elimination is slow and proceeds via concerted syn-elimination. One interesting finding is that ß-hydride elimination can be preferred to a greater extent than C-C bond formation for Ni, more so than with Pd, which defies the generally assumed trends that ß-hydride elimination is more facile with Pd than Ni. The discussion of these findings is informed by KIE experiments, DFT calculations, stoichiometric reactions, and rate studies. Additionally, this report details an in-depth analysis of a methodological manifold for practical dehydrogenation and should enable its application to challenges in organic synthesis.

Nickel-catalyzed acylation of vinylpyridine with alkylzincs under 1 atm CO.

A nickel-catalyzed acylation of vinylpyridines with CO at atmospheric pressure is reported, allowing for an expedient approach to synthesize ß-acyl pyridine derivatives with high regio- and chemoselectivity. The electron-withdrawing property of pyridine plays pivotal roles in activating the alkenyl group, thereby facilitating this carbonylative process. In addition to vinylpyridines, other alkenylheterocycles such as thiazole and quinoline were also suitable for this method.

Effect of PLGF and EZH2 Expression in Placenta Tissue on GDM Placental Structure and Pregnancy Outcome.

Objective: To explore the relationship between the expression of placental growth factor (PLGF) and Zeste homolog enhancer 2 (EZH2) in placental tissues of women with gestational diabetes (GDM), placental function, and pregnancy outcome. Methods: Select 100 women with GDM diagnosed in our hospital from January 2019 to May 2020 as the GDM group and 100 women with normal pregnancy at the same time as the control group. Detection and analysis of the expression levels of PLGF and EZH2 proteins in placental tissue after delivery of the two components. Observation of the expression of different PLGF and EZH2 proteins using an electron microscope, and analyze the ultrastructural changes in placental tissue of women with GDM. Finally, assess the differences in pregnancy outcomes. Results: The expression intensity of PLGF protein in the GDM group was higher than that in the control group (P < .001), and the expression intensity of EZH2 protein in the GDM group was lower than that in the control group (P < .001); the positive rate of PLGF protein in the GDM group was 67.00% higher than that of the control group 35.00% (P < .001), the positive rate of EZH2 protein in the GDM group was 15.00% lower than 33.00% in the control group (P = .003); the placental ultrastructural change rate of PLGF-positive GDM women was 71.64% higher than that in the negative expression group 45.45 % (P = .011); the placental ultrastructural change rate of EZH2 protein-positive GDM mothers was 33.33% lower than that of negative expression of A mixed 68.24% (P = .01); the incidence of premature infants (26.87%) and fetal respiratory distress (13.43%) in the PLGF-positive GDM group, the rate was higher than that in the negative expression group (9.09%, 0%) (P = .027, .04); the incidence of preterm infants in the EZH2 protein-positive GDM group (0.00%) was lower than that in the negative expression group (24.71%) (P = .03). Conclusion: The expression of PLGF is up-regulated and the expression of EZH2 is down-regulated in the placental tissue of GDM women, which causes ultrastructural changes in the placental tissue and increases the incidence of preterm birth and fetal respiratory distress to a certain extent.

Cobalt-Catalyzed Asymmetric Aza-Nozaki-Hiyama-Kishi (NHK) Reaction of α-Imino Esters with Alkenyl Halides.

Chromium-catalyzed enantioselective Nozaki-Hiyama-Kishi (NHK) reaction represents one of the most powerful approaches for the formation of chiral carbon-heteroatom bond. However, the construction of sterically encumbered tetrasubstituted stereocenter through NHK reaction still posts a significant challenge. Herein, we disclose a cobalt-catalyzed aza-NHK reaction of ketimine with alkenyl halide to provide a convenient synthetic approach for the manufacture of enantioenriched tetrasubstituted α-vinylic amino acid. This protocol exhibits excellent functional group tolerance with excellent 99 % ee in most cases. Additionally, this asymmetric reductive method is also applicable to the aldimine to access the trisubstituted stereogenic centers.

Cobalt-Catalyzed Enantioselective Reductive α-Chloro-Carbonyl Addition of Ketimine to Construct the ß-Tertiary Amino Acid Analogues.

ß-Tertiary amino acid derivatives constitute one of the most frequently occurring units in natural products and bioactive molecules. However, the efficient asymmetric synthesis of this motif still remains a significant challenge. Herein, we disclose a cobalt-catalyzed enantioselective reductive addition reaction of ketimine using α-chloro carbonyl compound as a radical precursor, providing expedient access to a diverse array of enantioenriched ß-quaternary amino acid analogues. This protocol exhibits outstanding enantioselectivity and broad substrate scope with excellent functional group tolerance. Preliminary mechanism studies rule out the possibility of Reformatsky-type addition and confirm the involvement of radical species in stereoselective addition process. The synthetic utility has been demonstrated through the rapid assembly of iterative amino acid units and oligopeptide, showcasing its versatile platform for late-stage modification of drug candidates.

IGF2BP2, an RNA-binding protein regulates cell proliferation and osteogenic differentiation by stabilizing SRF mRNA.

Osteoblast proliferation and osteogenic differentiation (OGD) are regulated by complex mechanisms. The roles in cell proliferation and OGD of RNA-binding proteins in the insulin-like growth factor 2 mRNA-binding protein (IGF2BP) family remain unclear. To elucidate this, we examined the differential expression of IGF2BP2 in OGD and osteoporosis, and the expression profile of IGF2BP2-binding RNA in vitro. We screened the GEO database for differential expression of IGF2BP in OGD and osteoporosis, and verified the RNAs interacting with IGF2BP2 via RNA immunoprecipitation sequencing assays. The proliferation and OGD of IGF2BP2- and serum response factor (SRF)-treated cells, and their regulatory mechanisms, were examined. IGF2BP2 was differentially expressed in OGD and osteoporosis. The RNA immunoprecipitation sequencing assay identified all of the RNAs that bind with IGF2BP2, and revealed SRF as a target of IGF2BP2. IGF2BP2 and SRF inhibition impaired MC3T3-E1 cell growth but promoted OGD. The mRNA stability analysis revealed that IGF2BP2 enhanced SRF mRNA stability against degradation. In summary, IGF2BP2 is a potential biomarker and therapeutic target for osteoporosis and OGD.

Improving the Enantioselectivity of CHMOBrevi1 for Asymmetric Synthesis of Podophyllotoxin Precursor.

(R)-ß-piperonyl-γ-butyrolactones are key building blocks for the synthesis of podophyllotoxin, which have demonstrated remarkable potential in cancer treatment. Baeyer-Villiger monooxygenases (BVMOs)-mediated asymmetric oxidation is a green approach to produce chiral lactones. While several BVMOs were able to oxidize the corresponding cyclobutanone, most BVMOs gave the (S) enantiomer while Cyclohexanone monooxygenase (CHMO) from Brevibacterium sp. HCU1 gave (R) enantiomer, but with a low enantioselectivity (75 % ee). In this study, we use a strategy called "focused rational iterative site-specific mutagenesis" (FRISM) at residues ranging from 6 Šfrom substrate. The mutations by using a restricted set of rationally chosen amino acids allow the formation of a small mutant library. By generating and screening less than 60 variants, we achieved a high ee of 96.8 %. Coupled with the cofactor regeneration system, 9.3 mM substrate was converted completely in a 100-mL scale reaction. Therefore, our work reveals a promising synthetic method for (R)-ß-piperonyl-γ-butyrolactone with the highest enantioselectivity, and provides a new opportunity for the chem-enzymatic synthesis of podophyllotoxin.

Genetic responses in sexual diploid and unisexual triploid goldfish (Carassius auratus) introduced into a high-altitude environment.

Anthropogenic biological invasions represent major concerns but enable us to investigate rapid evolutionary changes and adaptation to novel environments. The goldfish Carassius auratus with sexual diploids and unisexual triploids coexisting in natural waters is one of the most widespread invasive fishes in Tibet, providing an ideal model to study evolutionary processes during invasion in different reproductive forms from the same vertebrate. Here, using whole-genome resequencing data of 151 C. auratus individuals from invasive and native ranges, we found different patterns of genomic responses between diploid and triploid populations during their invasion of Tibet. For diploids, although invasive individuals derived from two different genetically distinct sources had a relative higher diversity (π) at the population level, their individual genetic diversity (genome-wide observed heterozygosity) was significantly lower (21.4%) than that of source individuals. Population structure analysis revealed that the invasive individuals formed a specific genetic cluster distinct from the source populations. Runs of homozygosity analysis showed low inbreeding only in invasive individuals, and only the invasive population experienced a recent decline in effective population size reflecting founder events. For triploids, however, invasive populations showed no loss of individual genetic diversity and no genetic differentiation relative to source populations. Regions of putative selective sweeps between invasive and source populations of diploids mainly involved genes associated with mannosidase activity and embryo development. Our results suggest that invasive diploids deriving from distinct sources still lost individual genetic diversity resulting from recent inbreeding and founder events and selective sweeps, and invasive triploids experienced no change in genetic diversity owing to their reproduction mode of gynogenesis that precludes inbreeding and founder effects and may make them more powerful invaders.

Association between ambient temperature exposure and pregnancy outcomes in patients undergoing in vitro fertilization in Shanghai, China: a retrospective cohort study.

STUDY QUESTION: Does ambient temperature exposure affect outcomes including clinical pregnancy and live birth in women undergoing IVF? SUMMARY ANSWER: Both extreme cold and hot ambient temperatures were significantly associated with adverse pregnancy outcomes of IVF cycles. WHAT IS KNOWN ALREADY: Heat exposure has been linked to adverse pregnancy outcomes worldwide. However, the effect of ambient temperature on infertile women undergoing IVF treatment is unclear. STUDY DESIGN, SIZE, DURATION: A retrospective cohort study was conducted from a database of 3452 infertile women who underwent their first fresh or frozen embryo transfer in the Shanghai First Maternity and Infant Hospital from April 2016 to December 2020. PARTICIPANTS/MATERIALS, SETTING, METHODS: Daily mean ambient temperature exposure for each patient was obtained based on their residential address. Temperature-stratified multiple logistic regression analysis was performed to investigate associations between temperature exposure and pregnancy outcomes after controlling for confounders. Vulnerable sub-groups were identified using forest plots. MAIN RESULTS AND THE ROLE OF CHANCE: The clinical pregnancy rate and live birth rate were 45.7% and 37.1%, respectively. Regarding clinical pregnancy, a higher temperature during cold weather was significantly associated with a higher pregnancy rate in the period about 11 weeks before ovarian stimulation (adjusted odds ratio (aOR) = 1.102, 95% CI: 1.012-1.201). Regarding live birth, an increased temperature during cold weather was significantly related to a higher live birth rate in the period after confirmation of clinical pregnancy or biochemical pregnancy, with the aORs of 6.299 (95% CI: 3.949-10.047) or 10.486 (95% CI: 5.609-19.620), respectively. However, a higher temperature during hot weather was negatively associated with the live birth rate in the periods after confirmation of clinical pregnancy or biochemical pregnancy, with the aORs at 0.186 (95% CI: 0.121-0.285) or 0.302 (95% CI: 0.224-0.406), respectively. Moreover, the decline in live birth rates during cold and hot weather was accompanied by increased rates of early miscarriage (P < 0.05). Stratified analyses identified susceptibility characteristics among the participants. LIMITATIONS, REASONS FOR CAUTION: Climate monitoring data were used to represent individual temperature exposure levels according to the patient's residential address in the study. We were not able to obtain information of personal outdoor activity and use of indoor air conditioners in this retrospective study, which may affect actual temperature exposure. WIDER IMPLICATIONS OF THE FINDINGS: This study highlights that the ambient temperature exposure should be taken into account during IVF treatment and afterwards. There is a need to be alert to extremes in cold and hot ambient temperatures, especially during the period of follicle development and pregnancy. With this knowledge, clinicians can scientifically determine the timing of IVF treatment and reinforce patients' awareness of self-protection to minimize adverse pregnancy outcomes associated with extreme temperatures. STUDY FUNDING/COMPETING INTEREST(S): This work was supported by a grant from the Clinical Research Plan of Shanghai Hospital Development Center [SHDC2020CR4080], a grant from the Science and Technology Commission of Shanghai Municipality [19411960500], and two grants from the National Natural Science Foundation of China [81871213, 81671468]. B.W.M. is supported by a NHMRC Investigator grant (GNT1176437). B.W.M. reports consultancy for ObsEva, and research grants from Merck KGaA, Ferring and Guerbet. The other authors have no conflict of interest to declare. TRIAL REGISTRATION NUMBER: N/A.

Molecular Origin of Wetting Characteristics on Mineral Surfaces.

Accurate determination of the wetting characteristics on mineral surfaces is critical for many natural processes and industrial applications where multiphase flow in porous media is involved. The wetting behaviors on mineral surfaces are controlled by water-mineral interactions, giving rise to various wetting characteristics, including contact line advancement, formation of precursor films, etc. However, a fundamental understanding of wetting characteristics on different mineral surfaces is still lacking at the molecular level. Here, utilizing a comprehensive set of molecular dynamics simulations, we investigate the wetting characteristics of water on various mineral surfaces and obtain the corresponding water-mineral interaction properties (including the areal density of water-mineral interaction energy and the work of adhesion of the water-mineral interface), mineral wettability, and structural and diffusion properties of water molecules near the surface. We show that the diffusion properties of water molecules on mineral surfaces play an important role in wetting characteristics. We find that the contact line tends to advance forward in the jumping mode or the rolling mode during the wetting process, which depends on the diffusion capacity of the water molecules on mineral surfaces. The corresponding evolution of the solid-liquid friction coefficient during dynamic spreading is also analyzed. We further demonstrate the strong impact of isomorphic substitution and charge-balancing counterions on wetting characteristics on the surfaces of clay minerals. It is shown that the introduction of charge-balancing counterions can shift the mineral surface from strongly hydrophilic to strongly hydrophobic and lead to completely different wetting characteristics. Our results provide a clearer picture of the molecular underpinnings in mineral wetting phenomena and deepen the understanding of the control of water-mineral interactions on the wetting properties.

Screening of Therapeutic Targets for Pancreatic Cancer by Bioinformatics Methods.

Pancreatic cancer (PC) has the lowest survival rate and the highest mortality rate among all cancers due to lack of effective treatments. The objective of the current study was to identify potential therapeutic targets in PC. Three transcriptome datasets, namely GSE62452, GSE46234, and GSE101448, were analyzed for differentially expressed genes (DEGs) between cancer and normal samples. Several bioinformatics methods, including functional analysis, pathway enrichment, hub genes, and drugs were used to screen therapeutic targets for PC. Fisher's exact test was used to analyze functional enrichments. To screen DEGs, the paired t-test was employed. The statistical significance was considered at p <0.05. Overall, 60 DEGs were detected. Functional enrichment analysis revealed enrichment of the DEGs in "multicellular organismal process", "metabolic process", "cell communication", and "enzyme regulator activity". Pathway analysis demonstrated that the DEGs were primarily related to "Glycolipid metabolism", "ECM-receptor interaction", and "pathways in cancer". Five hub genes were examined using the protein-protein interaction (PPI) network. Among these hub genes, 10 known drugs targeted to the CPA1 gene and CLPS gene were found. Overall, CPA1 and CLPS genes, as well as candidate drugs, may be useful for PC in the future.

Practical synthesis of unsymmetrical disulfides promoted by bromodimethylsulfonium bromide.

Oxidative cross-coupling of two thiols is the most direct tool for the synthesis of unsymmetrical disulfides and highly desirable across academia and industry. However, the inevitable formation of significant amounts of the corresponding symmetrical by-products is a major issue. We herein present a method toward the synthesis of unsymmetrical disulfides in which the homo-coupling of the thiols is effectively inhibited by adding the two thiols sequentially, taking advantage of rapid oxidation of the thiol by bromodimethylsulfonium bromide.

Three-Dimensional Visualization Reveals Pore-Scale Mechanisms of Colloid Transport and Retention in Two-Phase Flow.

Colloids are ubiquitous in the natural environment, playing an important role in facilitating the transport of absorbed contaminants. However, due to the complexities arising from two-phase flow and difficulties in three-dimensional observations, the detailed mechanisms of colloid transport and retention under two-phase flow are still not well understood. In this work, we visualize the colloid transport and retention during immiscible two-phase flow based on confocal microscopy. We find that the colloid transport and retention behaviors depend strongly on the flow rate and pore/grain size. At low levels of saturation (high flow rate) with the wetting liquid mainly present as pendular rings, the colloids can aggregate at the liquid filaments in small-grain packings and are uniformly distributed in large-grain packings. Through theoretical analysis of the pendular ring geometry, we elucidate the mechanism responsible for the strong dependence of colloid clogging behavior on solid grain size. Our results further demonstrate that even at dilute concentrations, colloids can alter the flow paths and the wetting fluid topology, suggesting a strong two-way coupling dynamics between immiscible two-phase flow and colloid transport and calling for improved predictive models to incorporate the overlooked clogging behavior.

Cost-Effectiveness of Dapagliflozin in Heart Failure with Preserved or Mildly Reduced Ejection Fraction: the DELIVER Trial.

PURPOSE: The DELIVER trial demonstrated the efficacy of dapagliflozin in reducing primary endpoint (cardiovascular (CV) mortality or worsening heart failure) for heart failure with mid-range ejection fraction (HFmrEF) and heart failure with preserved ejection fraction (HFpEF). This study assessed the economic and clinical effects of incorporating dapagliflozin into a standard treatment regimen for HFpEF and HFmrEF cases in China. METHODS: A multistate Markov model was used to assess the clinical and economic effects of adding dapagliflozin to the usual treatment regimen for HFpEF and HFmrEF. A log-logistic formula was used to represent the cumulative incidence of hospitalization, readmission, and CV mortality. A 5% annual discount was applied to all costs. The health outcome was the incremental cost-effectiveness ratio (ICER), measured using quality-adjusted life years (QALYs) and life years (LYs). The findings were examined using sensitivity and scenario analyses to assess robustness. RESULTS: In the HFpEF or HFmrEF population, the 11.2-year incremental QALYs was 0.15 and LYs was 0.2, yielding an ICER of $10,615.87 per QALY and $7,763.08 per LY. These ICER values are lower than China's per capita gross domestic product (GDP) of $12,752 in 2022. The one-way sensitivity analysis revealed that non-hospital CV death was the most influential parameter. Furthermore, there was a 68% chance that dapagliflozin was cost-effective as an additional treatment, given a willingness-to-pay limit of three times the GDP ($38,256). CONCLUSIONS: Dapagliflozin adjunctive therapy was cost-effective in patients with HFpEF or HFmrEF from the perspective of Chinese national insurance.

Compact Super Electron-Donor to Monolayer MoS2.

The surface functionalization of two-dimensional (2D) materials with organic electron donors (OEDs) is a powerful tool to modulate the electronic properties of the material. Here we report a novel molecular dopant, Me-OED, that demonstrates record-breaking molecular doping to MoS2, achieving a carrier density of 1.10 ± 0.37 × 1014 cm-2 at optimal functionalization conditions; the achieved carrier density is much higher than those by other OEDs such as benzyl viologen and an OED based on 4,4'-bipyridine. This impressive doping power is attributed to the compact size of Me-OED, which leads to high surface coverage on MoS2. To confirm, we study tBu-OED, which has an identical reduction potential to Me-OED but is significantly larger. Using field-effect transistor measurements and spectroscopic characterization, we estimate the doping powers of Me- and tBu-OED are 0.22-0.44 and 0.11 electrons per molecule, respectively, in good agreement with calculations. Our results demonstrate that the small size of Me-OED is critical to maximizing the surface coverage and molecular interactions with MoS2, enabling us to achieve unprecedented doping of MoS2.

Complete Chloroplast Genome of Hypericum perforatum and Dynamic Evolution in Hypericum (Hypericaceae).

Hypericum perforatum (St. John's Wort) is a medicinal plant from the Hypericaceae family. Here, we sequenced the whole chloroplast genome of H. perforatum and compared the genome variation among five Hypericum species to discover dynamic changes and elucidate the mechanisms that lead to genome rearrangements in the Hypericum chloroplast genomes. The H. perforatum chloroplast genome is 139,725 bp, exhibiting a circular quadripartite structure with two copies of inverted repeats (IRs) separating a large single-copy region and a small single-copy region. The H. perforatum chloroplast genome encodes 106 unique genes, including 73 protein-coding genes, 29 tRNAs, and 4 rRNAs. Hypericum chloroplast genomes exhibit genome rearrangement and significant variations among species. The genome size variation among the five Hypericum species was remarkably associated with the expansion or contraction of IR regions and gene losses. Three genes-trnK-UUU, infA, and rps16-were lost, and three genes-rps7, rpl23, and rpl32-were pseudogenized in Hypericum. All the Hypericum chloroplast genomes lost the two introns in clpP, the intron in rps12, and the second intron in ycf3. Hypericum chloroplast genomes contain many long repeat sequences, suggesting a role in facilitating rearrangements. Most genes, according to molecular evolution assessments, are under purifying selection.