Deep Learning Model for Prediction of Bronchopulmonary Dysplasia in Preterm Infants Using Chest Radiographs.

Bronchopulmonary dysplasia (BPD) is common in preterm infants and may result in pulmonary vascular disease, compromising lung function. This study aimed to employ artificial intelligence (AI) techniques to help physicians accurately diagnose BPD in preterm infants in a timely and efficient manner. This retrospective study involves two datasets: a lung region segmentation dataset comprising 1491 chest radiographs of infants, and a BPD prediction dataset comprising 1021 chest radiographs of preterm infants. Transfer learning of a pre-trained machine learning model was employed for lung region segmentation and image fusion for BPD prediction to enhance the performance of the AI model. The lung segmentation model uses transfer learning to achieve a dice score of 0.960 for preterm infants with ≤ 168 h postnatal age. The BPD prediction model exhibited superior diagnostic performance compared to that of experts and demonstrated consistent performance for chest radiographs obtained at ≤ 24 h postnatal age, and those obtained at 25 to 168 h postnatal age. This study is the first to use deep learning on preterm chest radiographs for lung segmentation to develop a BPD prediction model with an early detection time of less than 24 h. Additionally, this study compared the model's performance according to both NICHD and Jensen criteria for BPD. Results demonstrate that the AI model surpasses the diagnostic accuracy of experts in predicting lung development in preterm infants.

An X-Band CMOS Digital Phased Array Radar from Hardware to Software.

Phased array technology features rapid and directional scanning and has become a promising approach for remote sensing and wireless communication. In addition, element-level digitization has increased the feasibility of complicated signal processing and simultaneous multi-beamforming processes. However, the high cost and bulky characteristics of beam-steering systems have prevented their extensive application. In this paper, an X-band element-level digital phased array radar utilizing fully integrated complementary metal-oxide-semiconductor (CMOS) transceivers is proposed for achieving a low-cost and compact-size digital beamforming system. An 8-10 GHz transceiver system-on-chip (SoC) fabricated in 65 nm CMOS technology offers baseband filtering, frequency translation, and global clock synchronization through the proposed periodic pulse injection technique. A 16-element subarray module with an SoC integration, antenna-in-package, and tile array configuration achieves digital beamforming, back-end computing, and dc-dc conversion with a size of 317 × 149 × 74.6 mm3. A radar demonstrator with scalable subarray modules simultaneously realizes range sensing and azimuth recognition for pulsed radar configurations. Captured by the suggested software-defined pulsed radar, a complete range-azimuth figure with a 1 km maximum observation range can be displayed within 150 ms under the current implementation.

Retraction notice to "Design, synthesis, and biological evaluation of heterotetracyclic quinolinone derivatives as anticancer agents targeting topoisomerases" [Eur. J. Med. Chem. 190 (2020) 112074].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors. The authors regret to inform that they would like to withdraw this accepted article, due to serious errors in authorship, affiliations, material sources and supporting grant names/numbers. The authors sincerely apologize for these oversights and miscommunications the study caused.

A Spine Robotic-Assisted Navigation System for Pedicle Screw Placement.

Pedicle screw implantation has excellent treatment effects and is often used by surgeons in spinal fusion surgery. However, due to the complexity of human body anatomy, this surgical procedure is difficult and challenging, especially in minimally invasive surgery or patients with congenital anomalies and kyphoscoliosis deformity. In addition to the abovementioned factors, the surgical experience and technique of the surgeon also affect the recovery rates and complications of the patients after the surgical operation. Therefore, accurately performing pedicle screw implantation has is a constant topic of common concern for surgeons and patients. In recent years, with the technological development, robot-assisted navigation systems have gradually become adopted. These robot-assisted navigation systems provide surgeons with complete preoperative planning before surgery. The system provides 3D reconstructed images of each vertebra, allowing surgeons to understand the patient's physiological characteristics more quickly. It also provides 2D images of sagittal, coronal, axial and oblique planes so that surgeons can accurately perform pedicle screw placement plan. Previous studies have demonstrated the effectiveness of robot-assisted navigation systems for pedicle screw implantation procedures, including accuracy and safety assessments. This step-by-step protocol aims to outline a standardized surgical technique note for robotic-assisted pedicle screw placement.

Design, synthesis, and biological evaluation of heterotetracyclic quinolinone derivatives as anticancer agents targeting topoisomerases.

A series of thiochromeno[2,3-c]quinolin-12-one derivatives with various substitutions were synthesized and evaluated as topoisomerase (Topo) inhibitors. Six (8, 10, 12, 14, 19, and 26) of 23 compounds showed strong inhibitory activities against Topo-mediated DNA relaxation and proliferation of five human cell lines including breast (MDA-MB-231, MDA-MB-468 and MCF7), colorectal (HCT116) and non-small cell lung (H1299) cancers. Among these, compounds 14 and 26 exhibited full inhibitory activities against Topo I at 3 µM and Topo IIα at 1 µM. Cancer cells treated with 26 accumulated DNA damage and were arrested at the G2/M phase. With time, cells proceeded to apoptosis, as revealed by increased amounts of cells with fragmented DNA and cleavage of caspase-8 and -9. In contrast, normal breast epithelial cells showed low sensitivity to 26. Taken together, our study identifies 26 as a potent Topo dual-inhibitor with low toxicity to normal cells, and elucidates that the terminal amino group of N-2-aminoethylamino or N-3-aminopropylamino at the 6th position and 8,10-di-halogen substituents on thiochromeno[2,3-c]quinolin-12-one are critical for the Topo-inhibiting and cancer-killing activities.

In Vitro and in Planta Evaluation of Trichoderma asperellum TA as a Biocontrol Agent Against Phellinus noxius, the Cause of Brown Root Rot Disease of Trees.

Brown root rot (BRR), caused by the white rot fungus Phellinus noxius, is an epidemic disease of diverse broadleaved and coniferous tree species in many tropical and subtropical regions. Flooding and trenching control measures are difficult to implement, and chemical controls can have an adverse impact on ecosystems. Previous studies have provided in vitro evidence for the potential use of Trichoderma spp. for biocontrol of BRR. Here, we analyzed the in vitro antagonistic and mycoparasitic abilities of four Trichoderma spp. isolates against four P. noxius isolates in dual culture and Ficus microcarpa wood blocks. A convenient inoculation system based on root inoculation of a highly susceptible loquat (Eriobotrya japonica) with P. noxius-colonized wheat-oat grains was developed to examine the effect of Trichoderma treatment in planta. Preventive application of Trichoderma asperellum TA, the isolate showing high antagonistic activity in vitro, was effective in preventing and delaying the wilting of P. noxius-inoculated loquat cuttings in greenhouse trials. To understand the specific niche in which T. asperellum TA interacts with P. noxius, KOH-aniline blue fluorescence microscopy was used to investigate the colonization of loquat roots by P. noxius and/or T. asperellum TA. Dilution plating assays were also conducted to quantify Trichoderma populations in the rhizosphere and potting mix. T. asperellum TA was able to robustly establish in the rhizosphere and potting mix but with scarce root penetration limited to the superficial layer. We discuss the timing and strategy for applying antagonistic Trichodema sp. on living trees or in BRR-infested areas for BRR management.

Results of using robotic-assisted navigational system in pedicle screw placement.

Recent technical developments have resulted in robotic-assisted pedicle screw placement techniques. However, the use of robotic-assisted navigational techniques is still subject to controversy. This study aims to assess the accuracy and safety of a self-developed navigation system, the point spine navigation system (PSNS), for robotic-assisted pedicle screw placement surgery. Fifty-nine pedicle screws were implanted in three porcine vertebrae at the T6-T10 and L1-L5 levels, with the assistance of the PSNS. The navigation and planning system provides virtual surgical guide images, including sagittal, coronal, axial, oblique planes, and customized three-dimensional reconstructions for each vertebra to establish accurate pedicle screw trajectories and placement tracts. After pedicle screw placement, post-operative spiral computer tomographic scans were performed and screws were evaluated using the Gertzbein-Robbins classification. Differences between the actual pedicle screw position and pre-operative planning paths, including the angle, shortest distance, and entry trajectory were recorded. The 59 pedicle screw placements were all within a safe zone, and there was no spinal canal perforation or any other damage under postoperative computed tomography image data. Fifty-one screws were categorized as group A, seven screws were noted as group B, and one screw was identified as group E under the Gertzbein-Robbins classification. The mean entry point deviation was 2.71 ± 1.72°, mean trajectory distance was 1.56 ± 0.66 mm, and average shortest distance between two paths was 0.96 ± 0.73 mm. Pedicle placement remains a challenging procedure with high reported incidences of nerve and vascular injuries. The implementation of a robotic-assisted navigational system yields an acceptable level of accuracy and safety for the pedicle screw placement surgery.

Performance comparison of III-V//Si and III-V//InGaAs multi-junction solar cells fabricated by the combination of mechanical stacking and wire bonding.

The integration of III-V and Si multi-junction solar cells as photovoltaic devices has been studied in order to achieve high photovoltaic conversion efficiency. However, large differences in the coefficients of thermal expansion and the lattice parameters of GaAs, Si, and InGaAs have made it difficult to obtain high-efficiency solar cells grown as epilayers on Si and InP substrates. In this paper, two types of devices, including GaInP/GaAs stacked on Si (GaInP/GaAs//Si) and GaInP/GaAs stacked on InGaAs (GaInP/GaAs//InGaAs), are fabricated via mechanical stacking and wire bonding technologies. Mechanically stacked GaInP/GaAs//Si and GaInP/GaAs//InGaAs triple-junction solar cells are prepared via glue bonding. Current-voltage measurements of the two samples are made at room temperature. The short-circuit current densities of the GaInP/GaAs//Si and GaInP/GaAs//InGaAs solar cells are 13.37 and 13.66 mA/cm2, while the open-circuit voltages of these two samples are measured to be 2.71 and 2.52 V, respectively. After bonding the GaInP/GaAs dual-junction with the Si and InGaAs solar cells, the conversion efficiency is relatively improved by 32.6% and 30.9%, respectively, compared to the efficiency of the GaInP/GaAs dual-junction solar cell alone. This study demonstrates the high potential of combining mechanical stacked with wire bonding and ITO films to achieve high conversion efficiency in solar cells with three or more junctions.

Inhibition of Periodontitis Induction Using a Stimuli-Responsive Hydrogel Carrying Naringin.

BACKGROUND: Developing a drug carrier with favorable handling characteristics that can respond to environmental changes after inflammation, such as pH changes, may be beneficial for treating periodontitis. This study aims to investigate the preclinical feasibility of using naringin, a naturally derived polymethoxylated flavonoid compound with anti-inflammatory properties, to inhibit periodontitis induction via a thermogelling and pH-responsive injectable hydrogel. METHODS: The hydrogel was made of amphipathic carboxymethyl-hexanoyl chitosan (CHC), ß-glycerol phosphate (ß-GP), and glycerol. Thermogelling and pH-responsive characteristics of the hydrogel, as well as cell viability after treatment with the hydrogel containing naringin, were evaluated in vitro. Hydrogel was subgingivally delivered when experimental periodontitis was induced in vivo, and therapeutic effect was evaluated with microcomputed tomography imaging, histology, and expression of inflammation-associated genes, including toll-like receptor (TLR)2, the receptor for advanced glycation end products (RAGE), myeloid differentiation primary response gene-88, and tumor necrosis factor (TNF)-α. RESULTS: The hydrogel was consistently fluidic at 4°C but rapidly gelled at 37°C. Release of naringin was faster at pH 5.5 to 6.5, and viability was significantly promoted by treatment with 0.85% naringin. Naringin-carrying CHC-ß-GP-glycerol hydrogel sites showed significantly reduced periodontal bone loss (P <0.05) and inflammatory infiltration (P <0.01) as well as significantly downregulated TLR2 (P <0.05), RAGE (P <0.01), and TNF-α (P <0.05) relative to the sites with experimental periodontitis alone. CONCLUSION: Naringin-carrying CHC-ß-GP-glycerol colloidal hydrogel can be used to inhibit induction of experimental periodontitis with favorable handling and inflammation-responsive characteristics.

Organic Photosensitizers Incorporating Rigidified Dithieno[3,2-f:2',3'-h]quinoxaline Segment Tethered with Thiophene Substitutes for Dye-Sensitized Solar Cells.

Metal-free D-π-RS-π-A type sensitizers, consisting of triphenylamine as the electron donor, 2,3-bis(3-(2-ethylhexyl)-5-methylthiophen-2-yl)dithieno[3,2-f:2',3'-h]quinoxaline (DTQT) as the rigidified conjugation spacer (RS), thiophene as the π-spacer, and 2-cyanoacrylic acid as the acceptor/anchor, have broad absorption spectra ranging from 350 to 550 nm and a high molar extinction coefficient up to >46 200 M(-1) cm(-1). Under simulated AM 1.5 G illumination, the dye-sensitized solar cells (DSSCs) fabricated from the dyes exhibited light-to-electricity conversions in the range of 6.78% to 8.27%. The best efficiency is slightly higher than that of N719-based standard DSSC (7.92%). The efficiency can be further boosted to 8.51% by optimizing the concentration of LiI electrolyte.

Injectable insulin-lysozyme-loaded nanogels with enzymatically-controlled degradation and release for basal insulin treatment: In vitro characterization and in vivo observation.

Diabetes is a common global disease that causes immense suffering for individuals and huge costs for the health care system. To minimize complications such as organ degeneration, diabetic patients are required to undergo treatments to maintain the blood glucose level in the normal range, ideally mimicking normal insulin secretion. The normal physiological insulin secretion pattern in healthy individuals consists of a base (basal) level through the day and increased secretion after meals (bolus insulin). Thus effective treatments may combine long acting, low-level insulin therapy with boosts of short acting insulin and/or oral agents. To achieve long term management of basal insulin level, an injectable insulin-loaded gel composed of self-assembled nanoparticles from carboxymethyl-hexanoyl chitosan (CHC) and integrated lysozyme for controlled biodegradation and insulin release was developed. In vitro characterizations and evaluations confirmed that lysozyme was active on CHC and that the amount of lysozyme in a CHC hydrogel determined the degradation and insulin release rate. The degradation products were found to be highly cytocompatible using a cell assay. In vivo evaluation of the system in a diabetic mouse model revealed that the fasted blood glucose level could be maintained in the normal range for 10days with a single injection of insulin-loaded CHC-lysozyme gel. The insulin-loaded CHC-lysozyme gels clearly show promise for use as a novel injectable long-acting insulin delivery system, with potential to manage the basal insulin level for many days with a single injection.

Organic Dyes Incorporating the Dithieno[3,2-f:2',3'-h]quinoxaline Moiety for Dye-Sensitized Solar Cells.

New donor-acceptor'-acceptor-type sensitizers (QBT dyes), comprising arylamine as the electron donor, dithieno[3,2-f:2',3'-h]quinoxaline as the internal acceptor, and 2-cyanoacrylic acid as both the acceptor and anchor, have been synthesized. The QBT dyes have broad absorption spectra covering the range of λ=368-487 nm with a highest molar extinction coefficient of up to approximately 40 000 M(-1) cm(-1) . The light-to-electricity conversion efficiencies of the dye-sensitized solar cells (DSSCs) fabricated from the dyes range from 6.11 to 7.59 % under simulated AM 1.5 G illumination. Upon addition of a threefold concentration of chenodeoxycholic acid as the co-adsorbent, the best performance cell has a power-conversion efficiency of 8.41 %, which is higher than that of the N719-based standard DSSC (8.27 %).

Liberal versus restricted fluid resuscitation strategies in trauma patients: a systematic review and meta-analysis of randomized controlled trials and observational studies*.

OBJECTIVE: Hemorrhage is responsible for most deaths that occur during the first few hours after trauma. Animal models of trauma have shown that restricting fluid administration can reduce the risk of death; however, studies in patients are difficult to conduct due to logistical and ethical problems. To maximize the value of the existing evidence, we performed a meta-analysis to compare liberal versus restricted fluid resuscitation strategies in trauma patients. DATA SOURCES: Medline and Embase were systemically searched from inception to February 2013. STUDY SELECTION: We selected randomized controlled trials and observational studies that compared different fluid administration strategies in trauma patients. There were no restrictions for language, population, or publication year. DATA EXTRACTION: Four randomized controlled trials and seven observational studies were identified from 1,106 references. One of the randomized controlled trials suffered from a high protocol violation rate and was excluded from the final analysis. DATA SYNTHESIS: The quantitative synthesis indicated that liberal fluid resuscitation strategies might be associated with higher mortality than restricted fluid strategies, both in randomized controlled trials (risk ratio, 1.25; 95% CI, 1.01-1.55; three trials; I(2), 0) and observational studies (odds ratio, 1.14; 95% CI, 1.01-1.28; seven studies; I(2), 21.4%). When only adjusted odds ratios were pooled for observational studies, odds for mortality with liberal fluid resuscitation strategies increased (odds ratio, 1.19; 95% CI, 1.02-1.38; six studies; I(2), 26.3%). CONCLUSIONS: Current evidence indicates that initial liberal fluid resuscitation strategies may be associated with higher mortality in injured patients. However, available studies are subject to a high risk of selection bias and clinical heterogeneity. This result should be interpreted with great caution.

Long-term outcome of patients with acute cholecystitis receiving antibiotic treatment: a retrospective cohort study.

BACKGROUND: Few studies have followed patients who received antibiotic treatment for acute cholecystitis (AC). The present retrospective study investigated recurrence rates of AC and analyzed factors associated with recurrence after antibiotic treatment in adult AC patients. METHODS: We analyzed patients treated with antibiotics for AC between October 1, 2004, and November 30, 2010. A Cox proportional hazards model was used to identify factors associated with early recurrence. Generalized additive models were applied to detect the nonlinear effects of continuous covariates. RESULTS: The study included 226 patients (mean age: 62.2 years; 144 men [63.7 %]). The average duration of parenteral antibiotics was 8.0 days. Second-generation cephalosporins were administered to 199 patients (88.1 %). The Kaplan-Meier plot indicated that recurrences were more frequent within 100 days of AC; these were defined as early recurrences. The recurrence rate was 13.7 % (31/226) at a median follow-up of 308.5 days (early recurrences: 19/226 [8.4 %]). The duration of parenteral antibiotic use significantly correlated with early recurrence (hazard ratio: 0.83; 95 % confidence interval, 0.73-0.95; p = 0.005). Generalized additive models revealed that patients using parenteral antibiotics longer than 8 days were less likely to suffer from early recurrence. CONCLUSIONS: The rate of recurrence of AC in patients who received antibiotics alone was low. The recurrence rate was higher within 100 days of AC. Because of the inherent limitations of a retrospective study, further research is needed to identify factors associated with early recurrence.

A pH-responsive amphiphilic chitosan-pyranine core-shell nanoparticle for controlled drug delivery, imaging and intracellular pH measurement.

A pH-responsive multifunctional core-shell nanoparticle, named CHC-PY nanoparticle, was successfully synthesized through electrostatic interaction of a thin shell of fluorescent pyranine dye (PY) with amphiphilic carboxymethylhexanoyl chitosan (CHC) nanoparticles. Upon encapsulating an anticancer drug, camptothecin (CPT), the CHC-PY nanoparticles exhibited an excellent drug loading efficiency (>95%). The resulting CPT-loaded CHC-PY nanoparticles also exhibited efficient cell internalization and good pH-responsive behavior. After being internalized (via efficient endocytosis pathway), the presence of fluorescent PY shell showed a pH-dependent emission characteristic which allowed the internalized CHC-PY nanoparticles acting as an indicator to distinguish the acidic microenvironment of cancerous cells, compared with normal cells. The pH-sensitive PY shell also acted as a modulator to control the CPT release wherein a higher release rate was detected at lower pH value, which is essentially a potential therapeutic niche for anticancer purposes. This new type of CHC-PY core-shell nanoparticle provides multiple functionality, where a synergistic performance of nanotherapeutics, imaging and even diagnosis at a cellular resolution can be achieved simultaneously.

Real-time tracheal ultrasonography for confirmation of endotracheal tube placement during cardiopulmonary resuscitation.

OBJECTIVE: This study aimed to evaluate the accuracy of tracheal ultrasonography for assessing endotracheal tube position during cardiopulmonary resuscitation (CPR). METHODS: We performed a prospective observational study of patients undergoing emergency intubation during CPR. Real-time tracheal ultrasonography was performed during the intubation with the transducer placed transversely just above the suprasternal notch, to assess for endotracheal tube positioning and exclude esophageal intubation. The position of trachea was identified by a hyperechoic air-mucosa (A-M) interface with posterior reverberation artifact (comet-tail artifact). The endotracheal tube position was defined as endotracheal if single A-M interface with comet-tail artifact was observed. Endotracheal tube position was defined as intraesophageal if a second A-M interface appeared, suggesting a false second airway (double tract sign). The gold standard of correct endotracheal intubation was the combination of clinical auscultation and quantitative waveform capnography. The main outcome was the accuracy of tracheal ultrasonography in assessing endotracheal tube position during CPR. RESULTS: Among the 89 patients enrolled, 7 (7.8%) had esophageal intubations. The sensitivity, specificity, positive predictive value, and negative predictive value of tracheal ultrasonography were 100% (95% confidence interval [CI]: 94.4-100%), 85.7% (95% CI: 42.0-99.2%), 98.8% (95% CI: 92.5-99.0%) and 100% (95% CI: 54.7-100%), respectively. Positive and negative likelihood ratios were 7.0 (95% CI: 1.1-43.0) and 0.0, respectively. CONCLUSIONS: Real-time tracheal ultrasonography is an accurate method for identifying endotracheal tube position during CPR without the need for interruption of chest compression. Tracheal ultrasonography in resuscitation management may serve as a powerful adjunct in trained hands.

Multiplex PCR system for rapid detection of pathogens in patients with presumed sepsis - a systemic review and meta-analysis.

BACKGROUND: Blood culture is viewed as the golden standard for the diagnosis of sepsis but suffers from low sensitivity and long turnaround time. LightCycler SeptiFast (LC-SF) is a real-time multiplex polymerase chain reaction test able to detect 25 common pathogens responsible for bloodstream infections within hours. We aim to assess the accuracy of LC-SF by systematically reviewing the published studies. METHOD: Related literature on Medline, Embase, and Cochrane databases was searched up to October 2012 for studies utilizing LC-SF to diagnose suspected sepsis and that provided sufficient data to construct two-by-two tables. RESULTS: A total of 34 studies enrolling 6012 patients of suspected sepsis were included. The overall sensitivity and specificity for LC-SF to detect bacteremia or fungemia was 0·75 (95% CI: 0·65-0·83) and 0·92 (95%CI:0·90-0·95), respectively. LC-SF had a high positive likelihood ratio (10·10) and a moderate negative likelihood ratio (0·27). Specifically, LC-SF had a sensitivity of 0·80 (95%CI: 0·70-0·88) and a specificity of 0·95(95%CI: 0·93-0·97) for the bacteremia outcome, and a sensitivity of 0·61 (95%CI: 0·48-0·72) and a specificity of 0·99 (95%CI: 0·99-0·99) for the fungemia outcome. High heterogeneity was found in the bacteremia outcome subgroup but not in the fungemia outcome subgroup. CONCLUSION: LC-SF is of high rule-in value for early detection of septic patients. In a population with low pretest probability, LC-SF test can still provide valuable information for ruling out bacteremia or fungemia.

The impact of adding clinical assistants on patient waiting time in a crowded emergency department.

BACKGROUND: Emergency department (ED) crowding causes prolonged waiting times. OBJECTIVE: To evaluate the potential benefit of introducing clinical assistants to a busy and crowded ED. METHODS: This was a retrospective cohort study at an urban, academic tertiary medical centre. We introduced one clinical assistant to each ED shift. The main task of clinical assistants was managing the flow of incoming ED patients. The case group consisted of all adult non-trauma emergency patients during the case period from 1 September to 30 November 2008. The first control group consisted of all adult non-trauma emergency patients between 1 June and 31 August 2008 and the second control group consisted of all patients treated between 1 September and 30 November 2007. The primary outcome was the 'waiting time', defined as the time from triage to the time of the first medical order entered into the computer system. The secondary outcome was the number of adult non-trauma emergency patients who left the ED without being seen. RESULTS: There were 12 257 cases and 25 950 controls. The mean and median waiting times were significantly shorter in the case group. The mean waiting time of the case group was 20.86 min, which was 4.51 min (17.8%) shorter than that of the first control group and 7.41 min (26.2%) shorter than that of the second control group. The median waiting time of the case group was also significantly shorter than those of the control groups. The number of the patients who left without being seen was significantly smaller in the case period. CONCLUSIONS: In a busy and crowded ED, the introduction of clinical assistants to an existing emergency health service effectively reduces patient waiting times and decreases the number of patients leaving without being seen.