Electrochemical Synthesis of C(sp3)-Rich Amines by Aminative Carbofunctionalization of Carbonyl Compounds

Alkylamines form the backbone of countless nitrogen-containing small molecules possessing desirable biological properties. Despite advances in amine synthesis through transition metal catalysis and photoredox chemistry, multicomponent reactions that leverage inexpensive materials to transform abundant chemical feedstocks into three-dimensional α-substituted alkylamines bearing complex substitution patterns remain scarce. Here, we report the design of a catalyst-free electroreductive manifold that merges amines, carbonyl compounds and carbon-based radical acceptors under ambient conditions without rigorous exclusion of air and moisture. Key to this aminative carbofunctionalization process is the chemoselective generation of nucleophilic α-amino radical intermediates that readily couple with electrophilic partners, providing straightforward access to architecturally intricate alkylamines and drug-like scaffolds which are inaccessible by conventional means.

Molecular network mechanism in cerebral ischemia-reperfusion rats treated with human urine stem cells

Objective

To explore the effect of human urine-derived stem cells (husc) in improving the neurological function of rats with cerebral ischemia-reperfusion (CIR), and report new molecular network by bioinformatics, combined with experiment validation.

Methods

After CIR model was established, and husc were transplanted into the lateral ventricle of rats，neurological severe score (NSS) andgene network analysis were performed. Firstly, we input the keywords "Cerebral reperfusion" and "human urine stem cells" into Genecard database and merged data with findings from PubMed so as to get their targets genes, and downloaded them to make Venny intersection plot. Then, Gene ontology (GO) analysis, kyoto encyclopedia of genes and genomes (KEGG) pathway analysis and protein-protein interaction (PPI) were performed to construct molecular network of core genes. Lastly, the expressional level of core genes was validated via quantitative real-time polymerase chain reaction (qRT-PCR), and localized by immunofluorescence.

Results

Compared with the Sham group, the neurological function of CIR rats was significantly improved after the injection of husc into the lateral ventricle; at 14 days, P = 0.028, which was statistically significant. There were 258 overlapping genes between CIR and husc, and integrated with 252 genes screened from PubMed and CNKI. GO enrichment analysis were mainly involved neutrophil degranulation, neutrophil activation in immune response and platelet positive regulation of degranulation, Hemostasis, blood coagulation, coagulation, etc. KEGG pathway analysis was mainly involved in complement and coagulation cascades, ECM-receptor. Hub genes screened by Cytoscape consist ofCD44, ACTB, FN1, ITGB1, PLG, CASP3, ALB, HSP90AA1, EGF, GAPDH. Lastly, qRT-PCR results showed statistic significance (P < 0.05) in ALB, CD44 and EGF before and after treatment, and EGF immunostaining was localized in neuron of cortex.

Conclusion

husc transplantation showed a positive effect in improving neural function of CIR rats, and underlying mechanism is involved in CD44, ALB, and EGF network.

Discovery, Optimization, and Evaluation of Novel N-(Benzimidazol-5-yl)-1,3,4-thiadiazol-2-amine Analogues as Potent STAT3 Inhibitors for Cancer Treatment

Signal transducer and activator of transcription 3 (STAT3) is an attractive target for cancer therapy. However, identifying potent and selective STAT3 small-molecule inhibitors with drug-like properties remains challenging. Based on a scaffold combination strategy, compounds with a novel N-(benzimidazol-5-yl)-1,3,4-thiadiazol-2-amine scaffold were designed and their inhibition of the interleukin-6 (IL-6)/JAK/STAT3 pathway was tested in HEK-Blue IL-6 reporter cells. After optimization of lead compound 12, compound 40 was identified as a selective STAT3 inhibitor that directly binds the SH2 domain to inhibit STAT3 phosphorylation, translocation, and downstream gene transcription. Compound 40 exhibited antiproliferative activities against STAT3-overactivated DU145 (IC50 value = 2.97 μM) and MDA-MB-231 (IC50 value = 3.26 μM) cancer cells and induced cell cycle arrest and apoptosis. In the DU145 xenograft model, compound 40 showed in vivo antitumor efficacy following intraperitoneal administration, with a tumor growth inhibition rate of 65.3% at 50 mg/kg, indicating promise for further development.

Neuroprotective effect of salidroside on hippocampal neurons in diabetic mice via PI3K/Akt/GSK-3β signaling pathway

BACKGROUND

Diabetic encephalopathy is manifested by cognitive dysfunction. Salidroside, a nature compound isolated from Rhodiola rosea L, has the effects of anti-inflammatory and antioxidant, hypoglycemic and lipid-lowering, improving insulin resistance, inhibiting cell apoptosis, and protecting neurons. However, the mechanism by which salidroside alleviates neuronal degeneration and improves learning and memory impairment in diabetic mice remains unclear.

OBJECTIVE

To investigate the effects and mechanisms of salidroside on hippocampal neurons in streptozotocin-induced diabetic mice.

MATERIALS AND METHODS

C57BL/6 mice were randomly divided into 4 groups to receive either sham (control group (CON)), diabetes mellitus (diabetes group (DM)), diabetes mellitus + salidroside (salidroside group (DM + SAL)), and diabetes mellitus + salidroside + phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002 (diabetes mellitus + salidroside + LY294002 group (DM + SAL + LY294002)). After 12 weeks of diabetes onset, the cognitive behaviors were tested using Morris water maze. The number of hippocampal neurons was detected by Nissl staining. The expressions of PI3K, p-PI3K, Akt, p-Akt, GSK-3β, p-GSK-3β, cleaved caspase-3, caspase-3, Bax, Bcl-2, MAP2, and SYN in the hippocampus were detected by Western blot. Moreover, the expression of MAP2 and SYN in the hippocampus was further confirmed by immunofluorescence staining.

RESULTS

Salidroside increased the time of diabetic mice in the platform quadrant and reduced the escape latency of diabetic mice. Salidroside also increased the expression of p-PI3K, p-Akt, p-GSK-3β, MAP2, SYN, Bcl-2, while suppressed the expression of cleaved caspase-3, caspase3, and Bax in the DM + SAL group compared with the DM group (P < 0.05). The Nissl staining showed that the number of hippocampus neurons in the DM + SAL group was increased with the intact, compact, and regular arrangement, compared with the DM groups (P < 0.05). Interestingly, the protective effects of salidroside on diabetic cognitive dysfunction, hippocampal morphological alterations, and protein expressions were abolished by inhibition of PI3K with LY294002.

CONCLUSIONS

Salidroside exerts neuroprotective properties in diabetic cognitive dysfunction partly via activating the PI3K/Akt/GSK-3β signaling pathway.

RHOJ as a novel mechanosensitive modulator of endothelial inflammation

Physiological high shear stress (HSS), a frictional force generated by flowing blood, is essential for endothelial homeostasis under normal physiological conditions. HSS suppresses atherosclerosis by inhibiting endothelial inflammation. However, the molecular mechanisms underlying this process have not been fully elucidated. Here, we report that HSS downregulated the mRNA and protein levels of ras homolog family member J (RHOJ) in endothelial cells (ECs). Silencing endogenous RHOJ expression decreased the mRNA and protein levels of proinflammatory vascular cell adhesion molecule 1 (VCAM-1) and intercellular cell adhesion molecule 1 (ICAM-1) in ECs, leading to a reduction in monocyte adhesion to ECs. Conversely, the overexpression of RHOJ had the opposite effect. RNA-sequencing analysis uncovered several differentially expressed genes (such as yes-associated protein 1 (YAP1),heme oxygenase-1 (HO1), and monocyte chemoattractant protein-1 (MCP1)) and pathways (such as nuclear factor-kappa B (NF-κB), fluid shear stress and atherosclerosis, and cell adhesion pathways) as RHOJ targets. Additionally, HSS was observed to alleviate endothelial inflammation by inhibiting RHOJ expression. Finally, methylated RNA immunoprecipitation sequencing (MeRIP-seq) illustrated that fluid shear stress regulates RHOJ expression in an N6-methyladenosine (m6A)-dependent manner. Mechanistically, the RNA m6A writer, methyltransferase 3 (METTL3), and the RNA m6A readers, YTH N6-methyladenosine RNA-binding protein F 3 (YTHDF3) and YTH N6-methyladenosine RNA-binding protein C 1/2 (YTHDC1/2), are involved in this process. Taken together, our data demonstrate that HSS-induced downregulation of RHOJ contributes to endothelial homeostasis by suppressing endothelial inflammation and that RHOJ inhibition in ECs is a promising therapeutic strategy for endothelial dysfunction.

Laparoendoscopic single-site radical nephrectomy for localized renal cancer: a descriptive research study with at least a 10-year follow-up

Background

Laparoendoscopic single-site (LESS) surgery is performed to further narrow the incisions and reduce tissue injury. It has been more than10 years since the surgery was first described. However, there is still no report on the results of 10-year follow-up. This study evaluated the use of long-term oncology and the renal outcomes of LESS radical nephrectomy (LESS-RN) in the treatment of localized renal cancer.

Methods

We retrospectively analyzed the clinical data of patients treated with LESS-RN at Changhai Hospital from 2009 to 2012. Patients with localized kidney cancer who were followed-up for at least 10 years were included in the study. The baseline data and major perioperative outcome variables were analyzed. Overall survival (OS) and cancer-specific survival (CSS) were calculated using the Kaplan-Meier method.

Results

A total of 48 patients were included in the study, which had a median follow-up of 11 years (interquartile range, 10.7-11.8 years). The 10-year OS and CSS rates were 87.5% [42/48; 95% confidence interval (CI): 0.778-0.972] and 97.9% (47/48; 95% CI: 0.937-1.021), respectively. At the most recent follow-up, there were 5 patients with a chronic kidney disease stage ≥3. Among these 5 patients, 3 developed uremia and required continuous dialysis.

Conclusions

For localized renal cancer, LESS-RN is safe and effective with excellent long-term oncology controllability and good functional outcomes. Prospective studies with large sample sizes need to be conducted to validate our results.

Heralded and high-efficient entanglement concentrations based on linear optics assisted by time-delay degree of freedom

Entanglement concentration is a critical technique to prevent degraded fidelity and security in long-distance quantum communication. We propose novel practical entanglement concentration protocols (ECPs) for less-entangled Bell and Greenberger-Horne-Zeilinger states with unknown parameters by solely using simple linear optics. We avoid the need for the post-selection principles or photon-number-resolving detectors to identify the parity-check measurement completely by orchestrating auxiliary time degree of freedom, and the success of ECPs is exactly heralded by the detection signatures without destroying the incident qubits. Additionally, the outting incident photons kept are in the maximally entangled or the less-entangled state, and the success probability can be increased by recycling the latter. The heralded and the basic linear optical elements make our practical ECPs are accessible to experimental investigation with current technology.

Optimal dose of cefotaxime in neonates with early-onset sepsis: A developmental pharmacokinetic model-based evaluation

Objective: The perspective of real-world study is especially relevant to newborns, enabling dosage regimen optimization and regulatory approval of medications for use in newborns. The aim of the present study was to conduct a pharmacokinetic analysis of cefotaxime and evaluate the dosage used in newborns with early-onset sepsis (EOS) using real-world data in order to support the rational use in the clinical practice.

Methods: This prospective, open-label study was performed in newborns with EOS. A developmental pharmacokinetic-pharmacodynamic model of cefotaxime in EOS patients was established based on an opportunistic sampling method. Then, clinical evaluation of cefotaxime was conducted in newborns with EOS using real-world data.

Results: A one-compartment model with first-order elimination was developed, using 101 cefotaxime concentrations derived from 51 neonates (30.1–41.3°C weeks postmenstrual age), combining current weight and postnatal age. The pharmacokinetic-pharmacodynamic target was defined as the free cefotaxime concentration above MIC during 70% of the dosing interval (70% fT > MIC), and 100% of neonates receiving the dose of 50 mg/kg, BID attained the target evaluated using the model. Additionally, only two newborns had adverse reactions possibly related to cefotaxime treatment, including diarrhea and feeding intolerance.

Conclusion: This prospective real-world study demonstrated that cefotaxime (50 mg/kg, BID) had a favorable efficacy and an accepted safety profile for neonates with EOS.

Benzobis(imidazole) derivatives as STAT3 signal inhibitors with antitumor activity

Polycyclic aromatic systems have been considered good biological probes, but some may also be good scaffolds for drug development. In this study, a series of benzobis(imidazole) derivatives were identified as STAT3 signal inhibitors, among which compound 24 showed significant inhibition of IL-6 induced JAK/STAT3 signalling pathway activation. Moreover, 24 inhibited cancer cell growth and migration, and induced cell apoptosis as well as cycle arrest in human hepatocellular carcinoma cells (HepG2) and oesophageal carcinoma cells (EC109). Compound 24 also displayed obvious antitumor activity in a mouse HepG2 cell xenograft tumor model without affecting the body weight. These results confirmed that 24 was a potential STAT3 signal inhibitor with certain antitumor activity.

[Analysis of 2 diagnostic criteria of echocardiography for coronary artery aneurysm in Kawasaki disease]

Objective: To analyze the difference between Z score and previous criteria in the diagnosis characteristics of coronary artery aneurysm (CAA) in Kawasaki disease, and to investigate the clinical distribution of Kawasaki disease CAA in the Z score group. Methods: This study retrospectively analyzed the clinical and echocardiographic data of 2 419 children with Kawasaki disease in Shenzhen Children's Hospital from January 2009 to December 2019. The traditional criteria and Z score criteria were used to diagnose CAA, and the differences of diagnostic efficiency between the 2 diagnostic methods were analyzed. The clinical distribution characteristics of CAA in children with Kawasaki disease were analyzed by grouping their sex, clinical classification (complete Kawasaki disease, incomplete Kawasaki disease) the sensitivity to intravenous immunoglobulin (IVIG) (IVIG-sensitive Kawasaki disease,IVIG-unresponsive Kawasaki disease). And the course of the disease (≤6 weeks, >6-8 weeks, >8 weeks to 6 months) etc. The χ² test or Kruskal-Wallis test was used for comparison between the groups, and the Kappa test was used for consistency evaluation. Results: Among the 2 419 children with Kawasaki disease, 1 558 were males and 861 were females. The age of onset was 1.8 (1.0, 3.2) years. The rate of CAA by Z score criteria was higher than that by traditional method (21.9% (529/2 419) vs. 13.9% (336/2 419), χ²=1 074.94, P<0.001). Compared to the traditional method, the Z score criteria found higher rate of CAA in male patients, patients with incomplete Kawasaki disease, and IVIG-unresponsive patients (25.2% (392/1 558) vs. 16.0% (249/1 558), (32.7% (166/507) vs. 19.5% (99/507), 30.5% (95/312) vs. 24.0% (75/312), χ²=694.05, 216.19, 184.37, all P<0.001). The Z score criteria was consistent with the traditional method in diagnosing CAA (κ=0.642,P<0.001). Moreover, in the Z score criteria, the rate of CAA in males (25.2%, 392/1 558) was higher than that in females (15.9%, 137/861), higher in incomplete Kawasaki cases (32.7%, 166/507) than that in complete Kawasaki case (19.0%, 363/1 912), and higher in IVIG-unresponsive cases (30.4%, 95/312) than that in IVIG-sensitive cases (20.6%, 434/2 107), with statistically significant differences (χ²=27.76, 44.38, 15.43, all P<0.001). Coronary Z score of course ≤ 6 weeks was greater than that of course between>6-8 weeks and >8 weeks to 6 months (1.3 (0.7, 2.3) vs. 0.7 (0.3, 1.4), 0.7 (0.3, 1.3), Z=20.65, 13.70, both P<0.001). Conclusions: The rate of CAA in Kawasaki disease by Z score criteria is higher than that by traditional method. In the Z score group, most CAA occur within 6 weeks of the course of the disease, and the rate of CAA in male, incomplete Kawasaki disease, and IVIG-unresponsive is higher.

[Detection rate and clinical significance of regions of homozygosity in prenatal genetic diagnosis]

Objective: To detect the incidence and analyze the clinical significance of regions of homozygosity (ROH) through the single nucleotide polymorphism array (SNP array). Methods: The SNP array detection results of 5 116 pregnant women in the Third Affiliated Hospital of Guangzhou Medical University from January 2016 to December 2020 were retrospectively analyzed. The pregnant women with ROH (5 Mb as the threshold) were followed up to analyze the relationship between ROH and abnormal fetal phenotype. Whole exon sequencing was performed in 4 cases of consanguineous marriage to detect potential recessive causative genes in the ROH region. Results: (1) A total of 39 cases of ROH were detected, with a positive rate of 0.76% (39/5 116). Among them, 25 cases (64%, 25/39) were detected only on single chromosome, and chromosome 11 had the highest detection rate, suggesting the risk of uniparental disomy; fourteen cases (36%,14/39) were detected on multiple chromosomes, most commonly on chromosomes 11, 1, 3, 4 and 8. (2) The number of cases and detection rate of ROH detected by different prenatal diagnosis indicators were as follows: 12 cases (1.78%, 12/676) in pregnant women with abnormal non-invasive prenatal testing result, 12 cases (0.37%, 12/3 284) in pregnant women with ultrasound abnormality, 4 cases (4/4) in pregnant women with consanguineous marriage, 3 cases (0.92%, 3/326) in pregnant women with previous adverse pregnancy, 2 cases (1.15%, 2/174) in pregnant women with high risk of serology in screening, 2 cases (4.00%, 2/50) in pregnant women with abnormal fetal chromosomal karyotype, 2 cases (0.79%, 2/253) in pregnant women with advanced maternal age, 1 case (0.56%, 1/178) in pregnant women with related parental genetic factors and 1 case (0.58%, 1/171) in pregnant women with the other factors. (3) The follow-up results of 39 cases of prenatal ROH showed that there were 16 cases of term birth, 15 cases of termination of pregnancy, 2 cases of preterm births, 1 case of fetal death and 5 cases lost to follow-up. Conclusions: Chromosomal ROH phenomenon is not rare. By analyzing the detection rate of ROH in prenatal diagnosis, combined with the results of fetal phenotype and postpartum follow-up, the clinical characteristics of ROH are discussed, so as to better understand the relationship between ROH and its phenotype.

[Triptolide increases the radiosensitivity of lung cancer cells by inhibiting DNA repair and inducing apoptosis]

Objective: To investigate the effect of triptolide on radiosensitivity of lung cancer cells and its mechanism. Methods: The lung cancer cells H1299, A549, H157 and H838 were cultured. The strongest radio resistance cell line, H1299 was selected by cell clone formation experiment and for the subsequent experiments. 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2H tetrazolium bromide (MTT) was used to detect the effect of different concentrations of triptolide on the proliferation of H1299 cells. The optimal concentration of triptolide was 50nmol/L, and the optimal treatment time was 48 hours. The H1299 cells were divided into the control group, triptolide group (50 nmol/L), 4 Gy group and triptolide+ 4 Gy group. Flow cytometry was used to detect the apoptosis rate of H1299 cell. Western Blot was used to detect the proteins expression levels of p-Chk2, p-ATM, p-p53, Bcl-2, Bax and cleaved-Caspase 3. Results: The apoptotic rate and protein levels of Bax, cleaved-Caspase 3, p-Chk2, p-ATM and p-p53 in the 4 Gy group were (12.38±1.34)%, 0.42±0.04, 0.38±0.04, 0.98±0.11, 0.73±0.08, 0.95±0.09, respectively, higher than (3.26±2.43)%, 0.22±0.02, 0.23±0.03, 0.32±0.03, 0.21±0.02, 0.25±0.03 in the control group (P<0.05). However, the protein level of Bcl-2 was (0.52±0.05), lower than (0.93±0.09) of the control group (P<0.05). The survival fraction (0.462) and protein level of Bcl-2 (0.44±0.04) in the triptolide group were lower than those of the control group (0.702 and 0.93±0.09, P<0.05). The apoptotic rate and the protein levels of Bax and cleaved-Caspase 3 in the triptolide group were (9.27±1.08)%, 0.45±0.05, 0.41±0.04, respectively, higher than (3.26±2.43)%, 0.22±0.02, 0.23±0.03 in the control group (P<0.05), and the sensitization ratio in the triptolide group was 1.579. The apoptosis rate, Bax and cleaved Caspase 3 protein expression levels in triptolide + 4 Gy group were (26.53±2.19)%, 0.91±0.09 and 0.79±0.08, respectively, higher than (12.38±1.34)%, 0.42±0.04 and 0.38±0.04 in 4 Gy group (P<0.05). The expression level of Bcl-2 protein was (0.21±0.02), lower than (0.52±0.05) in 4 Gy group (P<0.05). Conclusion: Triptolide increases the radiosensitivity of radiation-induced lung cancer cells by inhibiting DNA repair and inducing apoptosis.

Correlations between the ECD spectra and absolute configuration of bridged-ring lactones: revisiting Beecham's rule

Bridged lactones frequently appear as structural fragments in natural products. To elucidate their stereochemistry using electronic circular dichroism (ECD) spectra, Beecham correlated the sign of the Cotton effect (CE) from the n → π* transition of lactones at approximately 220 nm with the skeleton of bridged lactones. By combining experimental and theoretical ECD analyses of various bridged lactones using time-dependent density functional theory calculations and a methodology for extracting core structures, Beecham's rule was revisited and revised to define the scope of application. Both the position of the β-C atom in the larger lactone system and the additive contribution of groups at β-C exerted effects on the sign of the CE. The revised rule provides an alternative way to interpret experimental ECD data in addition to quantum-chemical calculation for various bridged lactones.

Metabolomics Changes of Serum and Tissues in Mice Died of Acute Tetracaine Poisoning

Abstract

Objective To study the changes of metabolites in serum and tissues （kidney, liver and heart） of mice died of acute tetracaine poisoning by metabolomics, to search for potential biomarkers and related metabolic pathways, and to provide new ideas for the identification of cause of death and research on toxicological mechanism of acute tetracaine poisoning. Methods Forty ICR mice were randomly divided into control group and acute tetracaine poisoning death group. The model of death from acute poisoning was established by intraperitoneal injection of tetracaine, and the metabolic profile of serum and tissues of mice was obtained by ultra-high performance liquid chromatography-electrostatic field orbitrap high resolution mass spectrometry （UPLC-Orbitrap HRMS）. Multivariate statistical principal component analysis （PCA） and orthogonal partial least square-discriminant analysis （OPLS-DA） were used, combined with t-test and fold change to identify the differential metabolites associated with death from acute tetracaine poisoning. Results Compared with the control group, the metabolic profiles of serum and tissues in the mice from acute tetracaine poisoning death group were significantly different. Eleven differential metabolites were identified in serum, including xanthine, spermine, 3-hydroxybutylamine, etc.; twenty-five differential metabolites were identified in liver, including adenylate, adenosine, citric acid, etc.; twelve differential metabolites were identified in heart, including hypoxanthine, guanine, guanosine, etc; four differential metabolites were identified in kidney, including taurochenodeoxycholic acid, 11, 12-epoxyeicosatrienoic acid, dimethylethanolamine and indole. Acute tetracaine poisoning mainly affected purine metabolism, tricarboxylic acid cycle, as well as metabolism of alanine, aspartic acid and glutamic acid. Conclusion The differential metabolites in serum and tissues of mice died of acute tetracaine poisoning are expected to be candidate biomarkers for this cause of death. The results can provide research basis for the mechanism and identification of acute tetracaine poisoning.

Measurement of the Cosmic Ray Helium Energy Spectrum from 70 GeV to 80 TeV with the DAMPE Space Mission

The measurement of the energy spectrum of cosmic ray helium nuclei from 70 GeV to 80 TeV using 4.5 years of data recorded by the Dark Matter Particle Explorer (DAMPE) is reported in this work. A hardening of the spectrum is observed at an energy of about 1.3 TeV, similar to previous observations. In addition, a spectral softening at about 34 TeV is revealed for the first time with large statistics and well controlled systematic uncertainties, with an overall significance of 4.3σ. The DAMPE spectral measurements of both cosmic protons and helium nuclei suggest a particle charge dependent softening energy, although with current uncertainties a dependence on the number of nucleons cannot be ruled out.

Expression and characterization of anticoagulant activity of salivary protein alALP from Asian tiger mosquito Aedes albopictus

Several bioactive molecules isolated from the saliva of blood-sucking arthropods, such as mosquitoes, have been shown to exhibit potential anticoagulant function. We have previously identified a 30kDa allergen named Aegyptin-like protein (alALP), which is highly homologous to Aegyptin, from the salivary glands of female Aedes albopictus (Asian tiger mosquito). In this study, we identified the conserved functional domain of alALP by using bioinformatic tools, and expressed the His-tagged alALP recombinant protein in sf9 insect cells by generation and transfection of a baculoviral expression plasmid carrying the fulllength cDNA of alALP. We purified this recombinant protein and examined its function on the inhibition of blood coagulation. The results showed that the purified His-alALP prolonged the Activated Partial Thromboplastin Time (APTT), Prothrombin Time (PT) and Thrombin Time (TT) in vitro as well as the Bleeding Time (BT) in vivo, which suggest that alALP could be a novel anticoagulant.

Hyperparallel transistor, router and dynamic random access memory with unity fidelities

We theoretically implement some hyperparallel optical elements, including quantum single photon transistor, router, and dynamic random access memory (DRAM). The inevitable side leakage and the imperfect birefringence of the quantum dot (QD)-cavity mediates are taken into account, and unity fidelities of our optical elements can be achieved. The hyperparallel constructions are based on polarization and spatial degrees of freedom (DOFs) of the photon to increase the parallel efficiency, improve the capacity of channel, save the quantum resources, reduce the operation time, and decrease the environment noises. Moreover, the practical schemes are robust against the side leakage and the coupling strength limitation in the microcavities.

On-line quantitative analysis of heavy metals in water based on laser-induced breakdown spectroscopy

Heavy metal pollution from industrial wastewater is an important source. A method for heavy metals determination in industrial wastewater based on laser-induced breakdown spectroscopy (LIBS) technique was studied and the on-line monitoring system that used automatic graphite enrichment and spatial plasma confinement detection was developed and field demonstrated. The limits of detection (LOD) of heavy metal elements (Cd, Cr, Cu, Ni, Pb, Zn) could reach several μg/L. In Tongling, the on-line heavy metal monitor was field demonstrated. The calibration curves of copper and zinc were built on site, and then on-line monitoring was conducted. The measurement results of this monitor were compared with ICP-OES and had a good correlation. The results showed that the heavy metal monitor could be used for on-line detection of heavy metals in wastewater and had a good reliability.

Photocatalytic hydrogen evolution of 1-tetralones to α-naphthols by continuous-flow technology

A photoredox platform for the dehydrogenation of 1-tetralones to α-naphthols is disclosed. Further improvement is achieved using the continuous-flow approach.

[A comparative study of two ventilation modes in the weaning phase of preterm infants with respiratory distress syndrome]

OBJECTIVE

To compare the efficacy between synchronized intermittent mandatory ventilation (SIMV) and pressure support ventilation with volume guarantee (PSV+VG) in the weaning phase of preterm infants with respiratory distress syndrome (RDS).

METHODS

Forty preterm infants with RDS who were admitted to the neonatal intensive care unit between March 2016 and May 2017 were enrolled as subjects. All infants were born at less than 32 weeks' gestation and received mechanical ventilation. These patients were randomly and equally divided into SIMV group and PSV+VG group in the weaning phase. Ventilator parameters, arterial blood gas, weaning duration (from onset of weaning to extubation), duration of nasal continuous positive airway pressure (NCPAP) after extubation, extubation failure rate, the incidence rates of pneumothorax, patent ductus arteriosus (PDA) and bronchopulmonary dysplasia (BPD), and the mortality rate were compared between the two groups.

RESULTS

The PSV+VG group had significantly decreased mean airway pressure, weaning duration, duration of NCPAP after extubation, and extubation failure rate compared with the SIMV group (P<0.05). There were no significant differences in arterial blood gas, mortality, or incidence rates of pneumothorax, PDA and BPD between the two groups (P>0.05).

CONCLUSIONS

For preterm infants with RDS, the PSV+VG mode may be a relatively safe and effective mode in the weaning phase. However, multi-center clinical trials with large sample sizes are needed to confirm the conclusion.

Photoinduced hydroxylperfluoroalkylation of styrenes

“No Catalyst is Better” is confirmed in the hydroxylperfluoroalkylation of styrenes with perfluoroalkyl iodides under irradiation by visible light.

Tracking Co(I) Intermediate in Operando in Photocatalytic Hydrogen Evolution by X-ray Transient Absorption Spectroscopy and DFT Calculation

X-ray transient absorption spectroscopy (XTA) and optical transient spectroscopy (OTA) were used to probe the Co(I) intermediate generated in situ from an aqueous photocatalytic hydrogen evolution system, with [Ru^II(bpy)₃]Cl₂·6H₂O as the photosensitizer, ascorbic acid/ascorbate as the electron donor, and the Co-polypyridyl complex ([Co^II(DPA-Bpy)Cl]Cl) as the precatalyst. Upon exposure to light, the XTA measured at Co K-edge visualizes the grow and decay of the Co(I) intermediate, and reveals its Co-N bond contraction of 0.09 ± 0.03 Å. Density functional theory (DFT) calculations support the bond contraction and illustrate that the metal-to-ligand π back-bonding greatly stabilizes the penta-coordinated Co(I) intermediate, which provides easy photon access. To the best of our knowledge, this is the first example of capturing the penta-coordinated Co(I) intermediate in operando with bond contraction by XTA, thereby providing new insights for fundamental understanding of structure-function relationship of cobalt-based molecular catalysts.

Improved Photoelectrocatalytic Performance for Water Oxidation by Earth-Abundant Cobalt Molecular Porphyrin Complex-Integrated BiVO4 Photoanode

An earth-abundant, low-cost cobalt porphyrin complex (CoTCPP) is designed as a molecular catalyst to work on three-dimensional BiVO4 film electrode for water oxidation for the first time. Under illumination of a 100 mW cm(-2) Xe lamp, the CoTCPP-functionalized BiVO4 photoanode exhibits a 2-fold enhancement in photocurrent density at 1.23 V vs RHE and nearly a 450 mV cathodic shift at 0.5 mA cm(-2) photocurrent density relative to bare BiVO4 in 0.1 M Na2SO4 (pH = 6.8). Simultaneously, stoichiometric oxygen and hydrogen are generated with a faradic efficiency of 80% over 4 h. The activity and stability of the BiVO4 photoanode are dramatically increased by molecular CoTCPP, giving rise to higher performance than previously reported noble metal ruthenium complex-modified BiVO4 photoanode. By using hydrogen peroxide as the hole scavenger, we demonstrate that molecular CoTCPP catalyst greatly suppresses the hole-electron recombination on the surface of BiVO4 semiconductor, which offers a promising route toward high efficiency, low cost, practical solar fuel generation device.

Visible-Light-Driven Photocatalytic Activation of Inert Sulfur Ylides for 3-Acyl Oxindole Synthesis

Bicarbonyl-substituted sulfur ylide is a useful, but inert reagent in organic synthesis. Usually, harsh reaction conditions are required for its transformation. For the first time, it was demonstrated that a new, visible-light photoredox catalytic annulation of sulfur ylides under extremely mild conditions, permits the synthesis of oxindole derivatives in high selectivities and efficiencies. The key to its success is the photocatalytic single-electron-transfer (SET) oxidation of the inert amide and acyl-stabilized sulfur ylides to reactive radical cations, which easily proceeds with intramolecular C-H functionalization to give the final products.

Atomic-Scale Interfacial Magnetism in Fe/Graphene Heterojunction

Successful spin injection into graphene makes it a competitive contender in the race to become a key material for quantum computation, or the spin-operation-based data processing and sensing. Engineering ferromagnetic metal (FM)/graphene heterojunctions is one of the most promising avenues to realise it, however, their interface magnetism remains an open question up to this day. In any proposed FM/graphene spintronic devices, the best opportunity for spin transport could only be achieved where no magnetic dead layer exists at the FM/graphene interface. Here we present a comprehensive study of the epitaxial Fe/graphene interface by means of X-ray magnetic circular dichroism (XMCD) and density functional theory (DFT) calculations. The experiment has been performed using a specially designed FM₁/FM₂/graphene structure that to a large extent restores the realistic case of the proposed graphene-based transistors. We have quantitatively observed a reduced but still sizable magnetic moments of the epitaxial Fe ML on graphene, which is well resembled by simulations and can be attributed to the strong hybridization between the Fe 3d_z2 and the C 2p_z orbitals and the sp-orbital-like behavior of the Fe 3d electrons due to the presence of graphene.

[Effects of Shenfu injection on calreticulin expression and neuronal apoptosis in the cerebral cortex of neonatal rats with hypoxic-ischemic brain damage]

OBJECTIVE

To examine the expression of calreticulin (CRT) and the changes of intracellular free calcium and neuronal apoptosis in the cerebral cortex of neonatal rats with hypoxic-ischemic brain damage (HIBD), and to investigate the intervention effects of Shenfu injection.

METHODS

Seven-day-old rats were randomly assigned to three groups: control, hypoxic-ischemia (HI) and Shenfu-treated. Each group (n=50) was subdivided into 5 groups sacrificed at 3, 6, 12, 24 and 72 hours. Rat models of HIBD were prepared according to the Rice's method. Rats in the control group only underwent the separation of right common carotidartery. Shenfu injection was administered by intraperitoneal injections right after HI insults and then once daily at a dosage of 10 mL/kg for 3 days in the Shenfu-treated group. The expression of CRT in the cerebral cortex was detected by RT-PCR and Western blot. The free calcium concentrations were determined under a fluorescent microscope. The apoptosis rate was measured by the flow cytometry.

RESULTS

Compared with the control group, the expression levels of CRT in the HI and the Shenfu-treated groups were obviously up-regulated (P<0.05), and the expression levels of CRT in the Shenfu-treated group were notably higher than those in the HI group (P<0.05) at all time points. The concentrations of intracellular free calcium and the apoptosis rate of neurons in the cerebral cortex in the Shenfu-treated group were significantly reduced compared with those in the HI group (P<0.05), but increased significantly compared with those in the control group at all time points (P<0.05).

CONCLUSIONS

Shenfu injection may have neuroprotective effects against HIBD by up-regulation of CRT expression and relief of calcium overload.

Ferromagnetic interfacial interaction and the proximity effect in a Co2FeAl/(Ga,Mn)As bilayer

The magnetic properties of a Co2FeAl/(Ga,Mn)As bilayer epitaxied on GaAs (001) are studied both experimentally and theoretically. Unlike the common antiferromagnetic interfacial interaction existing in most ferromagnet-magnetic semiconductor bilayers, a ferromagnetic interfacial interaction in the Co2FeAl/(Ga,Mn)As bilayer is observed from measurements of magnetic hysteresis and x-ray magnetic circular dichroism. The Mn ions in a 1.36 nm thick (Ga,Mn)As layer remain spin polarized up to 400 K due to the magnetic proximity effect. The minor loops of the Co2FeAl/(Ga,Mn)As bilayer shift with a small ferromagnetic interaction field of +24 Oe and -23 Oe at 15 K. The observed ferromagnetic interfacial coupling is supported by ab initio density functional calculations. These findings may provide a viable pathway for designing room-temperature semiconductor spintronic devices through magnetic proximity effect.

Screening efficient siRNAs in vitro as the candidate genes for chicken anti-avian influenza virus H5N1 breeding

The frequent disease outbreaks caused by avian influenza virus (AIV) not only affect the poultry industry but also pose a threat to human safety. To address the problem, RNA interference (RNAi) has recently been widely used as a potential antiviral approach. Transgenesis, in combination with RNAi to specifically inhibit AIV gene expression, has been proposed to make chickens resistant to avian influenza. For the transgenic breeding, screening the efficient siRNAs in vitro as the candidate genes is one of the most important tasks. Here, we combined an online search tool and a series of bioinformatics programs with a set of rules for designing the siRNAs targeting different mRNA regions of AIV H5N1 subtype. By this method we chose five rational siRNAs, constructed five U6 promoter-driven shRNA expression plasmids contained the siRNA genes, and used these to produce stably transfected Madin-Darby canine kidney (MDCK) cells. Data from virus titration, IFA, PUI-stained flow cytometry, real-time quantitative RT-PCR and DAS-ELISA analyses showed that all five stably transfected cell lines were effectively resistant to viral replication when exposed to 100 CCID50 of AIV, and we finally chose the most effective plasmids (pSi-604i and pSi-1597i) as the candidates for making the transgenic chickens. These findings provide baseline information for breeding transgenic chickens resistant to AIV in combination with RNAi.

[Screening efficient siRNAs in vitro as the candidate genes for chicken anti-avian influenza virus H5N1 breeding]

The frequent disease outbreaks caused by avian influenza virus not only affect the poultry industry but also pose a threat to human safety. To address the problem, RNA interference (RNAi) has recently been widely used as a potential antiviral approach. Transgenesis in combination with RNAi to specifically inhibit avian enza virus gene expression has been proposed to make chickens resistant to the infection. For the transgenic breeding, screening in vitro efficient siRNAs as the candidate genes is one of the most important tasks. Here, we combined an online search tool and a series of bioinformatics programs with a set of rules for designing siRNAs targeted towards different mRNA regions of H5N1 avian influenza virus. Five rational siRNAs were chosen by this method, five U6 promoter-driven shRNA expression plasmids containing the siRNA genes were constructed and used for producing stably transfected MDCK cells. The data obtained by virus titration, IFA, PI-stained flow cytometry, real-time quantitative RT-PCR, and DAS-ELISA analyses showed that all five stably transfected cell lines we re resistant to virusreplication when exposed to 100 CCID50 of avian influenza virus H5N1. Finally, most effective plasmids (pSi-604i and pSi-1597i) as the candidates for making the transgenic chickens were chosen. These findings provide baseline information on use of RNAi technique for breeding transgenic chickens resistant to avian influenza virus.

Genetic analysis and gene mapping of a new rolled-leaf mutant in rice (Oryza sativa L.)

To understand the development of rice leaf blades, we identified a new rolled-leaf mutant, w32, from indica cultivar IR64 through EMS mutagenesis. The mutant showed a stable rolled-leaf phenotype throughout the life cycle. Two F2 populations were developed by crossing w32 to cultivar IR24 and PA64. Genetic analysis showed that the rolled-leaf phenotype was controlled by a single recessive gene. To determine the location of the gene, bulked segregant analysis was carried out using mutant and wild-type DNA pools and 1846 mutant-type F2 individuals derived from the cross w32/PA64 were genotyped to locate the gene on the short arm of chromosome 7. The rolled-leaf gene, tentatively named rl11(t), is likely a new gene as no other rolled-leaf genes have been identified near the region. By developing new SSR and InDel markers, the gene was delimited to a 52 kb region near the end of the short chromosome arm. Further fine mapping and cloning of the gene are currently underway.

Activated RHOA and peripheral axon regeneration

The regeneration of adult peripheral neurons after transection is slow, incomplete and encumbered by severe barriers to proper regrowth. The role of RHOA GTPase has not been examined in this context. We examined the expression, activity and functional role of RHOA GTPase and its ROK effector, inhibitors of regeneration, during peripheral axon outgrowth. We used qRT-PCR, quantitative immunohistochemistry, and assays of RHOA activation to examine expression in sensory neurons of rats with sciatic transection injuries. In vitro, we exposed dissociated adult sensory neurons, not grown on inhibitory substrates, to a RHOA-ROK inhibitor HA-1077 and measured neurite initiation and outgrowth. In vivo, we exposed early regenerating axons and Schwann cells directly to HA-1077 in a conduit connecting the proximal and distal stumps of transected sciatic nerves. Intact adult dorsal root ganglia sensory neurons expressed RHOA and ROK 1 mRNAs and protein and there were rises in RHOA after injury. Activated GTP-bound RHOA, undetectable in intact ganglia, was dramatically upregulated in both neurons and axons after injury. Adult rat sensory neurons in vitro demonstrated a dose-related increase in the initiation of neurite outgrowth, and in the proportion with long neurites when they were exposed to a ROK antagonist. Regenerative bridges that were directly exposed to the ROK inhibitor had a dose-related rise in the extent and distance of in vivo axon and partnered Schwann cell regrowth within them. RHOA activation and signaling are features of adult peripheral axon regeneration within its own milieu, independent of myelin. Inhibition of its activation may benefit peripheral axon lesions.

The influence of preamplifiers on the piezoelectric sensor's dynamic property

A charge amplifier or a voltage amplifier can be used as a signal conditioning circuit between a piezoelectric element and a meter or a data acquisition board. The outputs of the piezoelectric sensor are in an open-circuit state and a short-circuit state if a voltage amplifier and a charge amplifier are used, respectively. When the electrodes are in different states, the piezoelectric element has rather different stiffness and thus different sensor resonant frequency. This phenomenon is theoretically analyzed in detail and validated by a carefully designed experiment. The results indicate that a much wider range of working frequency is achieved when a voltage amplifier is used.

Affinity chromatography for purification of the modular protein growth factor receptor-bound protein 2 and development of a screening test for growth factor receptor-bound protein 2 Src homology 3 domain inhibitor using peroxidase-linked ligand

Growth factor receptor-bound protein 2 (Grb2) is an adapter protein involved in the Ras-dependent signaling pathway that plays an important role in human cancers initiated by oncogenic receptors. Grb2 is constituted by one Src homology 2 domain surrounded by two SH3 domains, and the inhibition of the interactions produced by these domains could provide an antitumor approach. In evaluating chemical libraries, to search for potential Grb2 inhibitors, it was necessary to elaborate a rapid test for their screening. We have developed, first, a batch method based on the use of an affinity column bearing a Grb2-SH3 peptide ligand to isolate highly purified Grb2. We subsequently describe a very rapid 96-well screening of inhibitors based on a simple competition between purified Grb2 and a peroxidase-coupled proline-rich peptide.

[Studies on the activity and immunohistochemistry of heme oxygenase in Schistosoma japonicum]

OBJECTIVE

To explore the activity of heme oxygenase and immunolocate the enzyme in the adult worms of Schistosoma japonicum.

METHODS

Microsomal protein was isolated from the homogenate of adult S. japonicum, heme degradation and effect of different pH conditions and buffers on degrading reaction were investigated by incubating microsomal protein with hemin. The slices of whole worm and cells of S. japonicum were prepared, distribution of HO in schistosome was studied by immunofluorescent and alkaline phosphatase(AP)-immunocytochemical assays.

RESULTS

Microsomal protein of adult worms can degrade the heme in vitro, the activity being 56.7 nmol bilirubin/(mg.min). The optimal pH was 8.7. Immunofluorescent and AP-immunocytochemical assays revealed that the HO distributed dispersively in the worm, and located in cytoplasm.

CONCLUSION

The presence of HO was firstly proved in S. japonicum.

A family-based and case-control association study of the NOTCH4 gene and schizophrenia

Recently a strong positive association between schizophrenia and Notch4 has been reported. Both individual markers and haplotypes showed association with the disease, with five markers (three microsatellites and two SNPs) being tested. In order to test this finding we genotyped these markers in the Han Chinese population using a sample of 544 cases and 621 controls as well as >300 trios. Analysis of allele, genotype and haplotype frequencies in both samples showed no association between the markers and the disease. Our results would indicate that a significant role for the Notch4 gene in schizophrenia can be ruled out in the Han Chinese. However, similar studies are necessary in the Caucasian population as linkage disequilibrium arrangements and founder effects may differ between these two populations.

Implication of protein S thrombin-sensitive region with membrane binding via conformational changes in the gamma-carboxyglutamic acid-rich domain

In the vitamin K-dependent protein family, only protein S (PS) contains a thrombin-sensitive region (TSR), located between the domain containing the gamma-carboxyglutamic acid and the first epidermal growth factor-like domain. To better define the role of TSR in the PS molecule, we expressed a recombinant human PS (rHPS) and its analogue lacking TSR (rTSR-less), and prepared factor Xa- and thrombin-cleaved rHPS. A peptide reproducing TSR (TSR-peptide) was also synthesized in an attempt to obtain direct evidence of the domain involvement in PS anticoagulant activity. In a coagulation assay, both rTSR-less and factor Xa-cleaved PS were devoid of activated protein C cofactor activity. The TSR-peptide did not inhibit rHPS activity, showing that TSR must be embedded in the native protein to promote interaction with activated protein C. The binding of rHPS to activated platelets and to phospholipid vesicles was not modified after factor Xa- or thrombin-mediated TSR cleavage, whereas the binding of rTSR-less was markedly reduced. This suggested a role for TSR in conferring to PS a strong affinity for phospholipid membranes. TSR-peptide did not directly bind to activated platelets or compete with rHPS for phospholipid binding. The results of the present study show that TSR may not interact directly with membranes, but probably constrains the gamma-carboxyglutamic acid-rich domain in a conformation allowing optimal interaction with phospholipids.

Inhibitors of Ras signal transduction as antitumor agents

Anarchic cell proliferation, observed in some leukemia and in breast and ovarian cancers, has been related to dysfunctioning of cytoplasmic or receptor tyrosine kinase activities coupled to p21 Ras. The growth factor receptor-bound protein 2 (Grb2) adaptor when complexed with Sos (Son of sevenless), the exchange factor of Ras, conveys the signal induced by tyrosine kinase-activated receptor to Ras by recruiting Sos to the membrane, allowing activation of Ras. This review shows how it is possible to stop the Ras-deregulated signaling pathway to obtain potential antitumor agents. Grb2 protein is comprised of one SH2 surrounded by two SH3 domains and interacts by means of its Src homology (SH2) domain with phosphotyrosine residues of target proteins such as the epidermal growth factor (EGF) receptor or the Shc adaptor. By means of its SH3 domains, Grb2 recognizes proline-rich sequences of Sos, leading to Ras activation. Inhibitors of SH2 and SH3 domains were designed with the aim of interrupting Grb2 recognition. On the one hand, using structural data and molecular modeling, peptide dimers or "peptidimers", made up of two proline-rich sequences from Sos linked by an optimized spacer, were developed. On the other, using the structure of the Grb2 SH2 domain complexed with a phosphotyrosine (pTyr)-containing peptide and molecular modeling studies, a series of N-protected tripeptides containing two phosphotyrosine or mimetic residues, with one pTyr sterically constrained, were devised. These compounds show very high affinities for Grb2 in vitro. They have been targeted into cells showing selective antiproliferative activity on tumor cells. These results suggest that inhibiting SH2 or SH3 domains of signaling proteins might provide antitumor agents.

Inhibition of the ras-dependent mitogenic pathway by phosphopeptide prodrugs with antiproliferative properties

Phosphopeptide prodrugs bearing two S-acyl-2-thioethyl (SATE) biolabile phosphate protections were developed. They are capable to inhibit the Shc/Grb2 interaction and MAP kinases (ERK1 and ERK2) phosphorylation in cellular assay. The S-acetyl-2-thioethyl (MeSATE) analogue showed an IC50 of 1 microM in the inhibition of the colony formation of tumor cell line NIH3T3/HER2.

Small peptides containing phosphotyrosine and adjacent alphaMe-phosphotyrosine or its mimetics as highly potent inhibitors of Grb2 SH2 domain

A series of small peptides with the sequence mAZ-pTyr-Xaa-Asn-NH(2), where Xaa denotes alpha-methylphosphotyrosine or its carboxylic mimetics, were synthesized as inhibitors of the Grb2 SH2 domain. Peptide 3 with (alpha-Me)pTyr as Xaa has the highest affinity for Grb2 (K(d) = 3 +/- 1 nM) and exhibits to date the best inhibitory activity (IC(50) = 11 +/- 1 nM) to displace PSpYVNVQN-Grb2 interaction in an ELISA test. The lower affinities of peptides with (alpha-Me)Tyr, (alpha-Me)Phe(4-CO(2)H), or (alpha-Me)Phe(4-CH(2)CO(2)H) as Xaa demonstrate the importance of a double charged phosphate group at the pY+1 position. Molecular modeling showed additional hydrogen bond interactions provided by the (alpha-Me)pTyr residue with the Grb2 SH2 domain. These results thus show that the effect of hydrophobic pY+1 residues, initially put forth to increased the binding affinities, can be further enhanced by a (-Me)pTyr residue which has both hydrophobic and hydrophilic properties.

A Sos-derived peptidimer blocks the Ras signaling pathway by binding both Grb2 SH3 domains and displays antiproliferative activity

With the aim of interrupting the growth factor-stimulated Ras signaling pathway at the level of the Grb2-Sos interaction, a peptidimer, made of two identical proline-rich sequences from Sos linked by a lysine spacer, was designed using structural data from Grb2 and a proline-rich peptide complexed with its SH3 domains. The peptidimer affinity for Grb2 is 40 nM whereas that of the monomer is 16 microM, supporting the dual recognition of both Grb2 SH3 domains by the dimer. At 50 nM, the peptidimer blocks selectively Grb2-Sos complexation in ER 22 (CCL 39 fibroblasts overexpressing epidermal growth factor receptor) cellular extracts. The peptidimer specifically recognizes Grb2 and does not interact with PI3K or Nck, two SH3 domain-containing adaptors. The peptidimer was modified to enter cells by coupling to a fragment of Antennapedia homeodomain. At 10 microM, the conjugate inhibits the Grb2-Sos interaction (100%) and MAP kinase (ERK1 and ERK2) phosphorylation (60%) without modifying cellular growth of ER 22 cells. At the same concentration, the conjugate also inhibits both MAP kinase activation induced by nerve growth factor or epidermal growth factor in PC12 cells, and differentiation triggered by nerve growth factor. Finally, when tested for its antiproliferative activity, the conjugate was an efficient inhibitor of the colony formation of transformed NIH3T3/HER2 cells grown in soft agar, with an IC50 of around 1 microM. Thus, the designed peptidimers appear to be interesting leads to investigate signaling and intracellular processes and for designing selective inhibitors of tumorigenic Ras-dependent processes.