Search Results (18)

Talaromycosis caused by Talaromyces marneffei is a life-threatening mycosis in patients with acquired immunodeficiency syndrome (AIDS). The gold-standard diagnostic method relies on time-consuming cultures, which delay treatment and increase mortality. In this study, we developed a rapid and sensitive droplet digital PCR (ddPCR) assay targeting the internal transcribed spacer (ITS) gene for detecting T. marneffei and compared its performance with blood culture and quantitative PCR (qPCR) assays. The ddPCR assay had a detection limit of one copy/reaction, making it 10-fold more sensitive than qPCR. It demonstrated 100% specificity for T. marneffei, with no cross-reactivity to 15 other fungal pathogens, six bacterial pathogens, and plasma from 119 AIDS patients without talaromycosis. In 119 AIDS patients with talaromycosis, ddPCR exhibited better overall sensitivity (92.44%) than blood culture (86.55%) and qPCR (87.29%). The sensitivity of ddPCR was 97.8% (89/91) and 75% (21/28) in plasma collected before and after antifungal therapy, respectively. Moreover, fungal load measured by ddPCR negatively correlated with the time to blood culture positivity. Fungal loads in patients receiving antifungal therapy were significantly lower than those in untreated patients. These findings indicate that ddPCR facilitates rapid diagnosis of T. marneffei infection in AIDS patients and can assist clinicians in evaluating treatment efficacy by quantifying fungal load. Full article

The development of high-impact denture base formulations that are suitable for digital light processing (DLP) 3D printing is demanding. Indeed, a combination of high flexural strength/modulus and high fracture toughness is required. In this contribution, eight urethane macromonomers (UMs1-8) were synthesized in a one-pot, two-step procedure. Several rigid diols were first reacted with two equivalents of trimethylhexamethylene diisocyanate. The resulting diisocyanates were subsequently end-capped with a free-radically polymerizable monomer bearing a hydroxy group. UMs1-8 were combined with the monofunctional monomer (octahydro-4,7-methano-1H-indenyl)methyl acrylate and a poly(ε-caprolactone)-polydimethylsiloxane-poly(ε-caprolactone) (PCL-PDMS-PCL) triblock copolymer (BCP1) as a toughening agent. The double-bond conversion, glass transition temperature (T_g), and mechanical properties (flexural strength/modulus, fracture toughness) of corresponding light-cured materials were measured (cured in a mold using a light-curing unit). The results showed that the incorporation of BCP1 was highly efficient at significantly increasing the fracture toughness, as long as the obtained networks exhibited a low crosslink density. The structure of the urethane macromonomer (nature of the rigid group in the spacer; nature and number of polymerizable groups) was demonstrated to be crucial to reach the desired properties (balance between flexural strength/modulus and fracture toughness). Amongst the evaluated macromonomers, UM1 and UM2 were particularly promising. By correctly adjusting the BCP1 content, light-cured formulations based on those two urethane dimethacrylates were able to fulfill ISO20795-1:2013 standard requirements regarding high-impact materials. These formulations are therefore suitable for the development of 3D printable high-impact denture bases. Full article

In this study, droplet digital PCR and deep bisulfite sequencing were used to study the absolute and active rDNA copy number (CN) and the effect of paternal age on human and mouse sperm. The absolute CN ranged from 98 to 404 (219 ± 47) in human and from 98 to 177 (133 ± 14) in mouse sperm. Methylation of the human upstream control element/core promoter (UCE/CP) region and the 5′ external transcribed spacer, as well as that of the mouse CP, the spacer promoter, and 28S rDNA, significantly increased with donor age and absolute CN. Overall, rDNA hypomethylation was much more pronounced in mouse sperm, with 101.7 ± 11.4 copies showing a completely (0%) unmethylated and 11.3 ± 2.8 (8.5%) a slightly methylated (1–10%) CP region, compared to humans with 25.7 ± 9.5 (12%) completely unmethylated and 83.0 ± 19.8 slightly methylated UCE/CP regions. Although the absolute CN was much higher in human sperm, the number of copies with a hypomethylated (0–10%) promoter was comparable in humans (108.7 ± 28.3) and mice (113.0 ± 12.2). However, in mice, the majority (77%) of all copies were completely unmethylated, whereas in humans a high percentage (38%) showed one or two single CpG methylation errors. These different germline methylation dynamics may be due to species differences in reproductive strategies and lifespan. Complete demethylation of the sperm rDNA promoter in mice may be essential for embryonic genome activation, which already occurs at the 2-cell stage in mice and at the 4–8-cell stage in humans. The paternal age effect has been conserved between humans and mice with some notable differences. In humans, the number of hypomethylated (0–10%) copies decreased with age, whereas in mice only the completely unmethylated copies decreased with age. The number of methylated rDNA copies (>1% in mice and >10% in humans) significantly increased with age. Full article

The research presented in this article seeks to identify the possible causes of reinforcement shadows (RS) on the surface of concrete test specimen produced under laboratory conditions. Different hypotheses about RS were selected based on factory practices and simulated in the study. The test specimens were cast horizontally in contact with steel form-facing surfaces coated with a water-soluble release agent. In addition, two scenarios were analysed during specimen production: reinforcing mesh was fixed using plastic spacers or tie wire. The analysis of the reinforcement shadows was based on visual inspection, taking photos, surface moisture content measurements, and colour variation analysis using the Natural Colour System. It was concluded that RS, which are typically characterized by darker lines, can be defined by the percentage of black colour present in the shadowed area compared to the percentage of black colour in the surrounding area. This percentage can be quickly assessed on a factory scale using digital colour readers that provide timely information. The reduced concrete cover thickness from 35 mm to 10 mm revealed light horizontal dark lines on the exposed surface. It was hypothesised that the gap of less than 10 mm between the reinforcing bars and the steel form-facing plate, along with the sieving effect of the fresh concrete, can retard the cement paste hydration process, resulting in unhydrated ferrite phases that contribute to the dark colour of the unhydrated cement. The release agent sprayed on the steel form-facing surface straight through the reinforcing mesh created a RS effect of the reinforcement on the exposed concrete surface. The absence of a release agent under steel rebars decreased the wettability at the interface between the formwork and fresh concrete, resulting in dark lines during the curing process. It is important to avoid such cases when manufacturing precast reinforced concrete elements. Quantitatively assessing RS and proposing a standardized method for calculation and categorization could be a new research direction in the future. Full article

Among the mycoparasites, Ampelomyces strains are studied in detail, particularly regarding their use as biocontrol agents (BCAs) of powdery mildew (PM) fungi, including their potential to replace conventional agrochemicals. Ampelomyces strains are characterized morphologically; their ribosomal DNA internal transcribed spacer (rDNA-ITS) regions and actin gene (ACT) fragments were sequenced and their mycoparasitic activity was analyzed. In the interaction between Ampelomyces strains and PM fungi, the spores of the mycoparasites germinate on plant leaves, and their hyphae then penetrate the hyphae of PM fungi. Ampelomyces hyphae continue their growth internally, initiating the atrophy of PM conidiophores and eventually their complete collapse. Following the successful destruction of PM hyphae by Ampelomyces, the mycoparasite produces new intracellular pycnidia in PM conidiophores. The progeny spores released by mature pycnidia become the sources of subsequent infections of intact PM hyphae. As a result, the number of Ampelomyces-inoculated PM colonies gradually declines, and the conidial release of PM colonies is inhibited after the first treatment. Almost all conidiophores of 5- and 10-day-old Ampelomyces-inoculated PM colonies undergo complete atrophy or collapse. Methodological advances and in-depth analyses of the Ampelomyces–PM interaction were recently published. In this review, we summarize the genetic and phylogenetic diversity, the timing of mycoparasitism and pycnidiogenesis, the results of quantitative and visual analyses using electrostatic and digital microscopy technologies, the PM biocontrol potential of Ampelomyces, and the potential commercialization of the mycoparasites. The information provided herein can support further biocontrol and ecological studies of Ampelomyces mycoparasites. Full article

NanoSheet-Gate-All-Around-FETs (NS-GAAFETs) are commonly recognized as the future technology to push the digital node scaling into the sub-3 nm range. NS-GAAFETs are expected to replace FinFETs in a few years, as they provide highly electrostatic gate control thanks to the GAA structure, with four sides of the NS channel entirely enveloped by the gate. At the same time, the NS rectangular cross-section is demonstrated to be effective in its driving strength thanks to its high saturation current, tunable through the NS width used as a design parameter. In this work, we develop a NS-GAAFET compact model and we use it to link peculiar single-device parameters to digital circuit performance. In particular, we use the well-known BSIM-CMG core solver for multigate transistors as a starting point and develop an ad hoc resistive and capacitive network to model the NS-GAAFET geometrical and physical structure. Then, we employ the developed model to design and optimize a digital inverter and a five-stage ring oscillator, which we use as a performance benchmark for the NS-GAAFET technology. Through Cadence Virtuoso SPICE simulations, we investigate the digital NS-GAAFET performance for both high-performance and low-power nodes, according to the average future node present in the International Roadmap for Devices and Systems. We focus our analysis on the main different technological parameters with regard to FinFET, i.e., the inner and outer spacers. Our results highlight that in future technological nodes, the choice of alternative low-K dielectric materials for the NS spacers will assume increasing importance, being as relevant, or even more relevant, than photolithographic alignment and resolution at the sub-nm scale. Full article

Textile-reinforced cement (TRC) composites can lead to significant material (and dimensional) savings compared to steel-reinforced concrete, particularly when applied in thin-walled structures such as façade panels, shells, etc. In conditions where the geometrical restrictions do not allow for sufficient anchorage, however, the exploitation of this reinforcement may be suboptimal and the TRC’s mechanical properties may decrease. As shown in the literature, the use of 3D textile reinforcement can lead to an improved anchorage in the reinforcement points and superior post-cracking behavior in terms of bending. The question remains as to whether similar improvements can be achieved using 3D spacer connections, inserted post-manufacturing of the textiles. Therefore, this research experimentally investigated the effect of discretely inserted spacer connections on the flexural properties and cracking behavior of TRCs. Six different TRC beam configurations—varying in the placement of the spacer connections over the span—were investigated. Moreover, a comparison was made with two additional configurations: one equivalent 2D TRC system (using the same in-plane textiles but without through-thickness connections) and one 3D TRC system using knitted 3D textiles (with spacer yarns uniformly distributed). The four-point bending tests were monitored via digital image correlation (DIC) to visualize the full-field cracking pattern. The experimental results showed that the spacer connections could strongly improve the post-cracking bending stiffness and the modulus of rupture (MOR) when placed close to the free end of the sample and could also lead to reduced crack widths when placed around the midspan. Full article

The results of an experimental investigation on pressure drop and heat transfer in spacer-filled plane channels, which are representative of Membrane Distillation units, are presented and discussed. Local and mean heat transfer coefficients were obtained by using Thermochromic Liquid Crystals and Digital Image Processing. The performances of a novel spacer geometry, consisting of spheres that are connected by cylindrical rods, and are hereafter named spheres spacers, were compared with those of more conventional woven and overlapped spacers at equal values of the Reynolds number Re (in the range ~150 to ~2500), the pitch-to-channel height ratio, the flow attack angle and the thermal boundary conditions (two-side heat transfer). For any flow rate, the novel spacer geometry provided the least friction coefficient and a mean Nusselt number intermediate between those of the overlapped and the woven spacers. For any pressure drop and for any pumping power, the novel spacer provided the highest mean Nusselt number over the whole Reynolds number range that was investigated. The influence of buoyancy was also assessed for the case of the horizontal channels. Under the experimental conditions (channel height H ≈ 1 cm, ΔT ≈ 10 °C), it was found to be large in empty (spacer-less) channels that were up to Re ≈ 1200 (corresponding to a Richardson number Ri of ~0.1), but it was much smaller and limited to the range Re < ~500 (Ri < ~0.5) in the spacer-filled channels. Full article

This paper studied an atomic layer etching (ALE) technique with a surface treatment function for InAlN/GaN heterostructures with AlN spacer layers. Various parameters were attempted, and 30 s O₂ + 15 W BCl₃ was chosen as the optimal recipe. The optimal ALE approach exhibited satisfactory etching results, with regard to the etch-stop effect, compared with other techniques. The atomic force microscopy (AFM) results showed an etching per cycle (EPC) value of 0.15 nm/cycle, with a 0.996 fit coefficient and root mean square (RMS) surface roughness of around 0.61 nm (0.71 nm for as-grown sample), which was the lowest in comparison with digital etching (0.69 nm), Cl₂/BCl₃ continuous etching (0.91 nm) and BCl₃ continuous etching (0.89 nm). X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy with energy dispersive X-ray spectroscopy measurements (STEM/EDS) verified the indium clustered phenomena at the bottom apex of V-pit defects in the epi structure of InAlN/GaN high electron mobility transistors (HEMTs) for the first time, in addition to the surface morphology optimization for the ALE under-etching technique used in this work. The resistor hall effect (Hall) and AFM measurements demonstrated that after 4 or 5 ALE cycles, the two-dimensional electron gas (2-DEG) density and RMS roughness were improved by 15% and 11.4%, respectively, while the sheet resistance (R_sh) was reduced by 6.7%, suggesting a good surface treatment function. These findings were important for realizing high-performance InAlN/GaN HEMTs. Full article

Background: This study compared the influence of three different radial spacers (60,90,120 microns) on the marginal gap adaptation by using computer-aided manufacturing (CAD-CAM) for producing monolithic zirconia reinforced lithium silicate (ZLS) ceramic crowns. Methods: A total of 45 abutment acrylic teeth were divided into three groups of different radial spacers (60, 90, and 120 microns). In each group 15 teeth were scanned by Omnicam intra oral scanner and ZLS crowns were ground. For each unit the marginal gap was evaluated at four regions of interest by scanning electronic microscope (SEM). To compare the marginal gap between the three groups a one-way ANOVA with post-hoc Bonferroni test was preformed (α = 0.05). Results: The marginal gap for a 60 microns (162.99 ± 16.25 µm) radial spacer was found significantly higher than 90 (41.85 ± 3.57 µm) and 120 (41.85 ± 5.3 µm) microns radial spacers (p < 0.05). Between 90- and 120-micron radial spacers no difference was obtained. (p < 0.05). Conclusions: A radial spacer of 60 microns showed a significantly higher marginal gap compared to 90 and 120 microns and was not clinically accepted (>120 microns). For both 90 and 120 microns the marginal gap was clinically accepted (<120 microns) with no difference between the groups. The radial spacer which should be optimum for CELTRA^® DUO crowns is 90 microns. Full article

This work presents a simple and innovative protocol employing a microfluidic paper-based analytical device (µPAD) for equipment-free determination of mercury. In this method, mercury (II) forms an ionic-association complex of tetraiodomercurate (II) ion (HgI₄²⁻_(aq)) using a known excess amount of iodide. The residual iodide flows by capillary action into a second region of the paper where it is converted to iodine by pre-deposited iodate to liberate I_2(g) under acidic condition. Iodine vapor diffuses across the spacer region of the µPAD to form a purple colored of tri-iodide starch complex in a detection zone located in a separate layer of the µPAD. The digital image of the complex is analyzed using ImageJ software. The method has a linear calibration range of 50–350 mg L⁻¹ Hg with the detection limit of 20 mg L⁻¹. The method was successfully applied to the determination of mercury in contaminated soil and water samples which the results agreed well with the ICP-MS method. Three soil samples were highly contaminated with mercury above the acceptable WHO limits (0.05 mg kg⁻¹). To the best of our knowledge, this is the first colorimetric µPAD method that is applicable for soil samples including mercury contaminated soils from gold mining areas. Full article

Debitterizing water contains a great amount of amygdalin, a potential toxic compound, so it is mandatory the degradation of amygdalin to reduce the water’s toxicity and environmental pollution. In this paper, the suspended mycelia in debitterizing water were firstly investigated by digital microscope, cold field emission scanning electron microscope, and internal transcribed spacers (ITS) high-throughput sequencing. Thereafter, the degradation of commercial amygdalin by the identified species was assessed by determining the changes of amygdalin content and the β-glucosidase activity. The results indicate that the mycelia matched with genus of lower fungi, mainly including Irpex, Trichoderma and white rot fungus. Among them, Irpex lacteus had a definite promoting effect on the degradation of amygdalin, which was not caused by producing β-glucosidase, and the suitable degrading colony numbers ranged from 6.4 × 10⁶ CFU/mL to 6.4 × 10⁷ CFU/mL. In conclusion, this research might provide a potential novel approach to treat debitterizing water, so as to reduce the water pollution in the processing industry of apricot kernels. Full article

Background: The frequent overexpression of gastrin-releasing peptide receptors (GRPRs) in human cancers provides the rationale for delivering clinically useful radionuclides to tumor sites using peptide carriers. Radiolabeled GRPR antagonists, besides being safer for human use, have often shown higher tumor uptake and faster background clearance than agonists. We herein compared the biological profiles of the GRPR-antagonist-based radiotracers [^99mTc]Tc-[N₄-PEGx-DPhe⁶,Leu-NHEt¹³]BBN(6-13) (N₄: 6-(carboxy)-1,4,8,11-tetraazaundecane; PEG: polyethyleneglycol): (i) [^99mTc]Tc-DB7 (x = 2), (ii) [^99mTc]Tc-DB13 (x = 3), and (iii) [^99mTc]Tc-DB14 (x = 4), in GRPR-positive cells and animal models. The impact of in situ neprilysin (NEP)-inhibition on in vivo stability and tumor uptake was also assessed by treatment of mice with phosphoramidon (PA). Methods: The GRPR affinity of DB7/DB13/DB14 was determined in PC-3 cell membranes, and cell binding of the respective [^99mTc]Tc-radioligands was assessed in PC-3 cells. Each of [^99mTc]Tc-DB7, [^99mTc]Tc-DB13, and [^99mTc]Tc-DB14 was injected into mice without or with PA coinjection and 5 min blood samples were analyzed by HPLC. Biodistribution was conducted at 4 h postinjection (pi) in severe combined immunodeficiency disease (SCID) mice bearing PC-3 xenografts without or with PA coinjection. Results: DB7, -13, and -14 displayed single-digit nanomolar affinities for GRPR. The uptake rates of [^99mTc]Tc-DB7, [^99mTc]Tc-DB13, and [^99mTc]Tc-DB14 in PC-3 cells was comparable and consistent with a radioantagonist profile. The radiotracers were found to be ≈70% intact in mouse blood and >94% intact after coinjection of PA. Treatment of mice with PA enhanced tumor uptake. Conclusions: The present study showed that increase of PEG-spacer length in the [^99mTc]Tc-DB7–[^99mTc]Tc-DB13–[^99mTc]Tc-DB14 series had little effect on GRPR affinity, specific uptake in PC-3 cells, in vivo stability, or tumor uptake. A significant change in in vivo stability and tumor uptake was observed only after treatment of mice with PA, without compromising the favorably low background radioactivity levels. Full article

III-V semiconductors are being considered as promising candidates to replace silicon channel for low-power logic and RF applications in advanced technology nodes. InGaAs is particularly suitable as the channel material in n-type metal-oxide-semiconductor field-effect transistors (MOSFETs), due to its high electron mobility. In the present work, we report on InGaAs FinFETs monolithically integrated on silicon substrates. The InGaAs channels are created by metal–organic chemical vapor deposition (MOCVD) epitaxial growth within oxide cavities, a technique referred to as template-assisted selective epitaxy (TASE), which allows for the local integration of different III-V semiconductors on silicon. FinFETs with a gate length down to 20nm are fabricated based on a CMOS-compatible replacement-metal-gate process flow. This includes self-aligned source-drain n⁺ InGaAs regrown contacts as well as 4 nm source-drain spacers for gate-contacts isolation. The InGaAs material was examined by scanning transmission electron microscopy (STEM) and the epitaxial structures showed good crystal quality. Furthermore, we demonstrate a controlled InGaAs digital etching process to create doped extensions underneath the source-drain spacer regions. We report a device with gate length of 90 nm and fin width of 40 nm showing on-current of 100 µA/µm and subthreshold slope of about 85 mV/dec. Full article

Among multi-gate field effect transistor (FET) structures, FinFET has better short channel control and ease of manufacturability when compared to other conventional bulk devices. The radio frequency (RF) performance of FinFET is affected by gate-controlled parameters such as transconductance, output conductance, and total gate capacitance. In recent years, high-k spacer dielectric materials for manufacturing nanoscale devices are being widely explored because of their better electrostatic control and being less affected by short channel effects (SCEs). In this paper, we aim to explore the potential benefits of using different Dual-k spacers on source and drain, respectively: (AsymD-kk) trigate FinFET structure to improve the analog/RF figure of merit (FOM) for low-power operation at 14 nm gate length. It has been observed from the results that the AsymD-kk FinFET structure improves the coupling of the gate fringe field to the underlap region towards the source and drain side, improving the transconductance (g_m) and output conductance (g_ds) at the cost of an increase in Miller capacitance. Furthermore, to reduce the drain field influence on the channel region, we also studied the effect of asymmetric drain extension length on a Dual-kk FinFET structure. It can be observed that the new asymmetric drain extension structures significantly improve the cutoff frequency (f_T) and maximum oscillation frequency (f_max) given the significant reduction of inner fringe capacitance towards drain side due to the shifting of the drain extension’s doping concentration away from the gate edge. Therefore, the asymmetric drain extension Dual-kk trigate FinFET (AsymD-kk_DE) is a new structure that combines different Dual-k spacers on the source and drain and asymmetric drain extension on a single silicon on insulator (SOI) platform to enhance the almost all analog/RF FOM. The proposed structure is verified by technology computer-aided design (TCAD) simulations with varying device physical parameters such as fin height, fin width, aspect ratio, spacer width, spacer material, etc. From comprehensive 3D device simulation, we have demonstrated that the proposed device is superior in performance to a conventional trigate FinFET and can be used to design low-power digital circuits. Full article