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Although there is significant progress in the research of carbon dots (CDs), some challenges such as difficulty in large-scale synthesis, complicated purification, low quantum yield, ambiguity in structure-property correlation, electronic structures, and photophysics are still major obstacles that hinder the commercial use of CDs. Recent advances in synthesis, modification, characterization, and applications of CDs are summarized in this review. We illustrate some examples to correlate process parameters, structures, compositions, properties, and performances of CDs-based materials. The advances in the synthesis approach, purification methods, and modification/doping methods for the synthesis of CDs are also presented. Moreover, some examples of the kilogram-scale fabrication of CDs are given. The properties and performance of CDs can be tuned by some synthesis parameters, such as the incubation time and precursor ratio, the laser pulse width, and the average molar mass of the polymeric precursor. Surface passivation also has a significant influence on the particle sizes of CDs. Moreover, some factors affect the properties and performance of CDs, such as the polarity-sensitive fluorescence effect and concentration-dependent multicolor luminescence, together with the size and surface states of CDs. The synchrotron near-edge X-ray absorption fine structure (NEXAFS) test has been proved to be a useful tool to explore the correlation among structural features, photophysics, and emission performance of CDs. Recent advances of CDs in bioimaging, sensing, therapy, energy, fertilizer, separation, security authentication, food packing, flame retardant, and co-catalyst for environmental remediation applications were reviewed in this article. Furthermore, the roles of CDs, doped CDs, and their composites in these applications were also demonstrated.

The study aimed to investigate whether there is a difference in the amount of adenosine per kilogram (mg/kg) between the patient groups that can and cannot be converted to sinus rhythm (SR) with adenosine therapy in patients with supraventricular tachycardia (SVT). This single-centered, retrospectively designed study was conducted in the ED of a training and research hospital between December 1, 2019 and December 1, 2022 on patients who were admitted to the ED with SVT diagnosis and treated with a 6–12–18 mg adenosine protocol. The main analyses were carried out in three stages. The first analysis was performed considering the first 6 mg dose of adenosine administered. The second analysis was performed by considering the 12 mg adenosine administered as the second dose because it did not respond to the first dose. Finally, the third analysis was performed by considering the 18 mg adenosine administered as the third dose because it did not respond to preciously dosages. The primary outcome variable was determined to be converting SR and created two groups according to this; the success SR group and the failure SR group. During the study period, 73 patients who were admitted to the ED with PSVT diagnosis and treated with intravenous adenosine were included. After the first 6 mg of adenosine treatment was administered to all 73 patients, SR was achieved in only 38% of patients. The mean adenosine dose (mg/kg) was significantly lower in the failure SR group, 0.07373 ± 0.014, compared with 0.08885 ± 0.017 mg/kg in the success SR group (mean difference with 95% CI: −0.01511 [−0.023 to −0.0071]; p < 0.001). In the second and third stage analyses, considering 12 and 18 mg adenosine doses, when the administrations with successful and failed SR were compared, no difference was found in terms of the applied adenosine doses per kilogram. This study suggest that the success of terminating SVT with the first 6 mg dose of adenosine appears to be dependent on patient weight. In patients given larger doses of adenosine, determinants of PSVT termination success may be factors other than patient weight.

The pecan nut is produced in 57 countries in the world. Alternate bearing is one of the main biological problems that affect pecan cultivation. Mineral and organic fertilization is a good strategy to maintain and increase pecan nut production. In this study, several mineral and organic doses of fertilization were tested using a factorial arrangement 56 bounded to 25 treatments was used in structure Taguchi L25: nitrogen (N) 0 - 240 kg ha-1, phosphate (P2O5) 0 - 120 kg ha-1, potassium (K2O) 0 - 100 kg ha-1, calcium (CaO) 0 - 400 kg ha-1, liquid humus 0 - 3600 L ha-1 and solid humus 0 - 8000 kg ha-1. The study was carried out in Aldama city, Chihuahua (Mexico). An average yield of 2.4 t ha-1 was obtained, 157 nuts per kilogram and 58.9% of edible nut. The average alternate bearing intensity was 31.58%, and the long-term yield index (IRLP) was 9.59%. It is concluded that the factors whit the greatest impact on the analyzed variables were N and P2O5. In addition, it was found these mineral and organic fertilization systems help to reduce alternate bearing in pecan and simultaneously improve production and long-term productivity index. Optimal fertilization doses were defined: 181.4 kg ha-1 of N, 93.5 kg ha-1 of P2O5 and 3287.2 L ha-1 of liquid humus. Finally, the mineral fertilization complemented with organic fertilization is considered a good fertilization strategy for pecan trees, to increase production and with lower environmental impact.

Roller-compacted concrete (RCC) for pavements has experienced problems with its physical-mechanical performance over extended periods due to ambient and in situ curing conditions. Accordingly, this study aimed to present multiple regression equations for calculating the physical-mechanical properties of RCC for pavements under different service and mix conditions. For this purpose, the research included two cement and two water contents, one reduced with admixture, and four combinations of temperature and relative humidity. For model calibration and definition of the equations, cubic and beam samples were fabricated to carry out physical-mechanical tests, such as moisture content, shrinkage, and modulus of rupture. Laboratory-obtained data were studied with the Response Surface Methodology (RSM) to determine the best regression equations. The main findings determined that the behavior of a mixture of RCC at a prolonged ambient exposure time is possible because the surface models and the RSM were consistent with the different service and mix conditions. The models showed an accuracy of 98.99% in detecting shrinkage changes from 12 to 16% cement with 5.65% water in dry to wet ambient conditions. Similarly, moisture content and modulus of rupture had a 98.27 to 98.88% fit. Finally, the drying shrinkage, with mixes of 12% cement and water content variations with water-reducing admixture and superplasticizer effects, had an adjustment of 94.87%.

To overcome the problems of commercial magnetic resonance imaging (MRI) contrast agents (CAs) ( i.e. , small molecule Gd chelates), we have proposed a new concept of Gd macrochelates based on the coordination of Gd 3+ and macromolecules, e.g. , poly(acrylic acid) (PAA). To further decrease the r 2 / r 1 ratio of the reported Gd macrochelates that is an important factor for T 1 imaging, in this study, a superior macromolecule hydrolyzed polymaleic anhydride (HPMA) was found to coordinate Gd 3+ . The synthesis conditions were optimized and the generated Gd-HPMA macrochelate was systematically characterized. The obtained Gd-HPMA29 synthesized in a 100 L of reactor has a r 1 value of 16.35 mM −1  s −1 and r 2 / r 1 ratio of 2.05 at 7.0 T, a high Gd yield of 92.7% and a high product weight (1074 g), which demonstrates the feasibility of kilogram scale facile synthesis. After optimization of excipients and sterilization at a high temperature, the obtained Gd-HPMA30 formulation has a pH value of 7.97, osmolality of 691 mOsmol/kg water, density of 1.145 g/mL, and viscosity of 2.2 cP at 20 ℃ or 1.8 cP at 37 ℃, which meet all specifications and physicochemical criteria for clinical injections indicating the immense potential for clinical applications. Graphical Abstract

In the proposed new SI, the kilogram will be redefined in terms of the Planck constant and the mole will be redefined in terms of the Avogadro constant. These redefinitions will have some consequences for measurements in chemistry. The goal of the Mole Project (IUPAC Project Number 2013-048-1-100) was to compile published work related to the definition of the quantity ‘amount of substance’, its unit the ‘mole’, and the consequence of these definitions on the unit of the quantity mass, the kilogram. The published work has been reviewed critically with the aim of assembling all possible aspects in order to enable IUPAC to judge the adequateness of the existing definitions or new proposals. Compilation and critical review relies on the broadest spectrum of interested IUPAC members.

Background This study aimed to determine whether drug doses per kilogram of lean body mass (LBM) were associated with dose-limiting toxicity (DLT) events in head and neck cancer (HNC) patients. Methods This retrospective cohort study included 179 HNC patients who underwent induction chemotherapy (IC) at a medical center from May 1, 2014, to May 31, 2021. HNC patients’ characteristics, tumor factors, IC regimen and dose, laboratory data, and body composition factors, including lean body mass (LBM) and skeletal muscle index (SMI), derived from CT, MRI, or PET scan images and drug dose per kilogram LBM were recorded. Dose-limiting toxicity (DLT) events were regarded as the primary outcome. Multivariate logistic regression was used to establish a novel risk score for DLT events by the abovementioned variables. The above-mentioned risk score was validated in another cohort. Results The overall DLT events during the first cycle of IC for 179 HNC patients was 24%. After stratifying by gender, docetaxel per kilogram LBM > 2.52 mg/kg (adjusted odds ratio [aOR]: 3.18; 95% confidence interval [CI], 1.25–8.09), pre-treatment glutamic pyruvic transaminase (GPT) > 40 U/L (aOR, 2.61; 95% CI, 1.03–6.64), and history of chronic liver diseases (aOR, 3.98; 95% CI, 1.03–15.46) were significant variables in male HNC patients. The DLT events risk was categorized by summation of the above-mentioned risk factors for male HNC patients. Three risk groups were stratified by overall event of 17.6%, 25.8%, and 75%. The above-mentioned risk score had an acceptable discriminatory ability in another validation cohort. Conclusions Among male HNC patients treated with IC, docetaxel per kilogram LBM more than 2.52 mg/kg, pre-treatment GPT > 40 U/L, and history of chronic liver disease were significant risk factors for DLT events. Identifying high-risk patients could help physicians prevent severe/fatal complications among HNC patients undergoing IC, especially for the male individuals.

At the intersection of taxonomy and nomenclature lies the scientific practice of typification. This practice occurs in biology with the use of holotypes (type specimens), in geology with the use of stratotypes, and in metrology with the use of measurement prototypes. In this paper I develop the first general definition of a scientific type and outline a new philosophical theory of types inspired by Pierre Duhem. I use this general framework to resolve the necessity-contingency debate about type specimens in philosophy of biology, to advance the debate over the myth of the absolute accuracy of standards in metrology, and to address the definition-correlation debate in geology. I conclude that just as there has been a productive synergy between philosophical accounts of natural kinds and scientific taxonomic practices, so too there is much to be gained from developing a deeper understanding of the practices and philosophy of scientific types.

The International System of Units (SI), the current form of the metric system and the world’s most used system of units, has been continuously updated and refined since the Metre Convention of 1875 to ensure that it remains up to date with the latest scientific and technological advances. The General Conference on Weights and Measures, at its 26th meeting in 2018, decided to adopt stipulated values of seven physical constants linked to seven measurement units (the second, meter, kilogram, ampere, kelvin, mole, and candela). This paper reviews the technologies developed, in intense and long-standing work, to determine the Avogadro and Planck constants, which are now integral to realising the kilogram.

The paper proposes an alternative approach to the dissemination of the mass unit in the context of the new definition of the kilogram. Considering the fact that redefinition allows mass to be directly realized at any value, the paper presents a model of the dissemination of mass which can be used for different series in grams, where the measurements are performed in the downward direction, but using 1 g as the reference standard (whose mass value is assumed to be determined after the redefinition using the capacitive or electrostatic techniques). The subdivision method presented (suitable for 1 weights) has as its starting point the approach used by Mihailov-Romanowski for the calibration of series in kilograms which uses an orthogonal system of equations. Thus, according to this method, a solution for obtaining the orthogonality of a system can be the use as defining standard of the ratio between the mass having the highest nominal value in the set and the standard (unit). The results obtained for a set of weights from 10 to 1 g using the subdivision method, in accordance with the Mihailov-Romanowski principle, are validated with those obtained with the multiplication method, where the measurements start from 1 to 10 g, as in the case of the kilogram series. The mass values obtained with both methods are equal, while the estimated uncertainties are slightly different, yet insignificant. The results obtained previously for the same sequence of weights using the traditional dissemination method, where the 1 kg standard is used as reference, are also presented in the paper. The results show that only three weights out of six have a mass value insignificantly different by 1 x 10 -4 mg compared to those obtained with the methods presented in this article, but, in terms of uncertainty, there are some differences. The way of disseminating the mass unit presented in this article can be extended to other different sequences of nominal values such as: (5...1) g, (20...1) g, (50...1) g or (500...100) g if the reference standard is 100 g.