•We empirically examine the determinants of technological innovation of BRICS.•We applied advanced panel data techniques.•Increase in human capital, R&D, GDP, FDI spillover improve technological ...innovation.•Human capital strengthens the link between technological innovation and spillovers .
The issue of knowledge spillovers, and technological innovation has received immense importance, particularly in the Fourth Industrial Revolution. In this context, this endeavor to carry out this study aims to empirically examine the determinants of technological innovation of Brazil, Russia, India, China, and South Africa (BRICS) countries, using the data that spans from the year 1990 to 2017. Moreover, this study further aims to investigate the role of human capital in mediating the relationship between the spillovers, through imports, foreign direct investment, and the technological progress that will prevail. This study is confined to the employment of the Westerlund (2007) cointegration and augmented mean group (AMG) method for the analysis. The cointegration method outcomes show that there is a stable, long-run equilibrium relationship among the variables in all the five models that have been considered. The results of the AMG method show that in the long run, an increase in the gross domestic product, human capital, research and development expenditures, and the foreign direct investment spillovers, increases the technological innovation in BRICS economies. The results also suggest that an improvement in the human capital strengthens the relationship between technological innovation and the spillovers. Hence, the knowledge spillovers and the developed human capital are more likely to affect the total technological innovation.
Ni/NiO core–shell nanowires on nickel foam (NF) are successfully synthesized using an “acid‐hungry” strategy. The 3D electrode with large accessible active sites and improved conductivity, possesses ...an optimized ionic and electronic transport path during electrochemical processes. High areal capacitance of 1.65 F cm−2 is obtained at an ultrahigh current density of 100 mA cm−2, which is 19.88 times higher than pristine NF. The direct growth of nanowires makes the present supercapacitor electrode robust for long‐term cycling test. By virtue of the favorable hydrogen adsorption energies on Ni0 and OHads energy on NiO or NiOOH, the 3D electrode exhibits high performance in hydrogen evolution reaction with 146 mV at η10 mA cm−2 and Tafel value of 72 mV dec−1, and oxygen evolution reaction with 382 mV at η10 mA cm−2 and Tafel value of 103 mV dec−1 in 1 m KOH. An electrolyzer using 3D electrodes as both anode and cathode can yield a current density of 10 mA cm−2 at 1.71 V, and possesses superior long‐term stability to an electrolyzer consisting of Pt/C||Ir/C. The present work develops an effective and low‐cost method for the large‐scale fabrication of Ni/NiO core–shell nanowires on commercial NF, providing a promising candidate for supercapacitors, fuel cells, and electrocatalysis.
Ni@NiO nanowires on nickel foam (ANF@NW) are facilely prepared via an “acid hungry” strategy. ANF@NW shows an ideal ion and electron transport path for high supercapacitor performance. Meanwhile, such a 3D electrode possesses bifunctional hydrogen evolution reaction and oxygen evolution reaction properties due to the favorable hydrogen adsorption energies on Ni0 and OHads energy on NiO or NiOOH.
To realize the molecular design of new functional silver(I) clusters, a new synthetic approach has been proposed, by which the weakly coordinating ligands NO3 – in a Ag20 thiolate cluster precursor ...can be substituted by carboxylic ligands while keeping its inner core intact. By rational design, novel atom-precise carboxylic or amino acid protected 20-core Ag(I)-thiolate clusters have been demonstrated for the first time. The fluorescence and electrochemical activity of the postmodified Ag20 clusters can be modulated by alrestatin or ferrocenecarboxylic acid substitution. More strikingly, when chiral amino acids were used as postmodified ligands, CD-activity was observed for the Ag20 clusters, unveiling an efficient way to obtain atom-precise chiral silver(I) clusters.
Using polyhedral oligomeric silsesquioxane (POSS) modified by a thiol group as a protected ligand, atom‐precise multi‐heteorocluster‐based dendrimers Ag12@POSS6 (1 a and 1 b) were assembled. Through ...the reactive −SH groups, six POSS shell ligands stabilize the central 12‐core silver(I) cluster by diverse Ag−S interactions. When such Ag12@POSS6 complex was stimulated by different solvents (acetone or tetrahydrofuran), the core Ag12 silver(I) cluster underwent reversible structural transformation between flattened cubo‐octahedral (in 1 a) and normal cubo‐octahedral (in 1 b); concomitantly shell POSS clusters rearranged from pseudo‐octahedral to quasi‐octahedral. Furthermore, the film matrix modified by 1 a or 1 b showed different hydrophobicity.
An atom‐precise Ag12@POSS6 dendritic complex (POSS=polyhedral oligomeric silsesquioxane) has been synthesized. The central silver(I) cluster core underwent a reversible structural transformation with solvent stimuli, leading to the rearrangement of the shell POSS clusters from pseudo‐octahedral to quasi‐octahedral.
Impatiens L. is one of the largest angiosperm genera, containing over 1000 species, and is notorious for its taxonomic difficulty. Here, we present, to our knowledge, the most comprehensive ...phylogenetic analysis of the genus to date based on a total evidence approach. Fortyâsix morphological characters, mainly obtained from our own investigations, are combined with sequence data from three genetic regions, including nuclear ribosomal ITS and plastid atpBârbcL and trnLâF. We include 150 Impatiens species representing all clades recovered by previous phylogenetic analyses as well as three outgroups. Maximumâparsimony and Bayesian inference methods were used to infer phylogenetic relationships. Our analyses concur with previous studies, but in most cases provide stronger support. Impatiens splits into two major clades. For the first time, we report that species with threeâcolpate pollen and four carpels form a monophyletic group (clade I). Within clade II, seven wellâsupported subclades are recognized. Within this phylogenetic framework, character evolution is reconstructed, and diagnostic morphological characters for different clades and subclades are identified and discussed. Based on both morphological and molecular evidence, a new classification outline is presented, in which Impatiens is divided into two subgenera, subgen. Clavicarpa and subgen. Impatiens; the latter is further subdivided into seven sections.
Self‐assembly of metavanadate and organosilver(I) salts leads to a novel dodecahedrane‐like Ag30(tBuS)2010+ silver(I) thiolate nanocage that tightly wraps an unusual C2h polyoxovanadate anion. The ...polyoxovanadate core undergoes transformation to a D3d configuration upon acidification, and reverts back to its original C2h structure upon addition of base. Chromism was observed for the silver(I) thiolate cluster during the configurational change of the central polyoxovanadate core; the color of the solution changes reversibly from green to dark yellow. This work represents the first reported example of chromic polyoxometalate‐templated silver(I) thiolate shells that respond to external acid–base stimuli. It also represents an important advance in providing crystallographic proof that structural transformations occur in a nanoscale core–shell cluster.
Silver cage: Self‐assembly of metavanadate and organosilver(I) salts generates a dodecahedrane‐like silver(I) thiolate Ag30(tBuS)2010+ nanocage that tightly wraps a polyoxovanadate core. Single‐crystal X‐ray crystallography was used to show that the core undergoes a reversible C2h to D3d configurational transformation in response to acid/base stimuli, which also result in a color change from green to dark yellow.
Abstract Background An alternative treatment for low rectal cancer is the cylindrical technique. We aim to compare the outcomes of patients undergoing conventional abdominoperineal resection (APR) ...versus cylindrical APR. Methods A prospective, randomized, open-label, parallel controlled trial was conducted between January 2008 and December 2010. Sixty-seven patients with T3-T4 low rectal cancer were identified during the study period (conventional n = 32, cylindrical n = 35). Results Patients who received cylindrical APR had less operative time for the perineal portion ( P < .001), larger perineal defect ( P < .001), less intraoperative blood loss ( P = .001), larger total cross-sectional tissue area ( P < .001), similar total operative time ( P = .096), and more incidence of perineal pain ( P < .001). The local recurrence of the cylindrical APR group was improved statistically ( P = .048). Conclusions Cylindrical APR in the prone jackknife position has the potential to reduce the risk of local recurrence without increased complications when compared with conventional APR in the lithotomy position for the treatment of low rectal cancer.
A novel discrete open high‐nuclearity nest‐like silver thiolate cluster complex, Ag33S3(StBu)16(CF3COO)9(NO3)(CH3CN)2(NO3) (1), has been isolated with nitrate and S2− anions acting as ...structure‐directing templates. Its similar nest‐like structure has been assembled into an extended layer Ag31S3(StBu)16(NO3)9n (2) by adjustment of auxiliary ligand. More interestingly, both complexes exhibit temperature‐dependent luminescence of high sensitivity with a large fluorescence enhancement (12‐fold for 1, 21‐fold for 2), which can be easily recognized by the naked‐eye (dramatic red‐shift Δ=104 nm for 1, larger Δ=113 nm for 2 at 77 K compared to those at 298 K). The correlation between luminescent thermochromism and temperature‐dependent variation of the coordination modes of template NO3− anion, Ag⋅⋅⋅S and Ag⋅⋅⋅Ag distances are also elucidated through variable‐temperature single‐crystal X‐ray crystal structure (VT‐SCXRD) analyses.
Stirring up a nest: A novel discrete open high‐nuclearity nest‐like silver thiolate cluster complex, Ag33S3(StBu)16(CF3COO)9(NO3)(CH3CN)2(NO3) (1), has been isolated with nitrate and S2− anions acting as structure‐directing templates. Its similar nest‐like structure has been assembled into an extended layer Ag31S3(StBu)16(NO3)9n (2) by adjustment of auxiliary ligand. Both complexes exhibit temperature‐dependent luminescence of high sensitivity with a large fluorescence enhancement (see figure).
Dolastatin 10 (Dol-10), a leading marine pentapeptide isolated from the Indian Ocean mollusk
, contains three unique amino acid residues. Dol-10 can effectively induce apoptosis of lung cancer cells ...and other tumor cells at nanomolar concentration, and it has been developed into commercial drugs for treating some specific lymphomas, so it has received wide attention in recent years. In vitro experiments showed that Dol-10 and its derivatives were highly lethal to common tumor cells, such as L1210 leukemia cells (IC
= 0.03 nM), small cell lung cancer NCI-H69 cells (IC
= 0.059 nM), and human prostate cancer DU-145 cells (IC
= 0.5 nM), etc. With the rise of antibody-drug conjugates (ADCs), milestone progress was made in clinical research based on Dol-10. A variety of ADCs constructed by combining MMAE or MMAF (Dol-10 derivatives) with a specific antibody not only ensured the antitumor activity of the drugs themself but also improved their tumor targeting and reduced the systemic toxicity. They are currently undergoing clinical trials or have been approved for marketing, such as Adcetris
, which had been approved for the treatment of anaplastic large T-cell systemic malignant lymphoma and Hodgkin lymphoma. Dol-10, as one of the most medically valuable natural compounds discovered up to now, has brought unprecedented hope for tumor treatment. It is particularly noteworthy that, by modifying the chemical structure of Dol-10 and combining with the application of ADCs technology, Dol-10 as a new drug candidate still has great potential for development. In this review, the biological activity and chemical work of Dol-10 in the advance of antitumor drugs in the last 35 years will be summarized, which will provide the support for pharmaceutical researchers interested in leading exploration of antitumor marine peptides.
PDF