Flicker noise contributed by active mixers usually compromises the overall sensitivity level of direct-conversion receivers (DCRs). In this article, a qualitative quasi-analytical model has been ...developed to in-depth explain the flicker noise mechanism existing in the switched-g m active mixer in which an improved current source switch is presented for high mixer common-mode rejection ratio (MCMRR). The built model simply explains how frequency translations take place within the mixer. Compact equations are derived to estimate the flicker noise contribution of individual stages at the output. Simulations validate the accuracy of the predictions, and the dependence of flicker noise on local oscillator (LO) slope ratio, period, and other circuit parameters. The high-frequency limitation of the mixer is further estimated by investigating into the tail parasitic capacitance charging and discharging behavior. Furthermore, a switched-g m pMOS mixer prototype with low flicker noise is implemented in a 0.18-<inline-formula> <tex-math notation="LaTeX">\mu \text{m} </tex-math></inline-formula> CMOS process. It operates at an RF input frequency of 1 GHz and provides a maximal conversion gain of 12.9 dB and an NF of 11.4 dB while a flicker noise corner of 220 kHz and an IIP3 of 3.6 dBm are measured, respectively. The mixer core only consumes 3.3 mW from a 1.8 V supply.
An increasing number of extremely preterm (EP) infants have survived worldwide. However, few data have been reported from China. This study was designed to investigate the short-term outcomes of EP ...infants at discharge in Guangdong province.
A total of 2051 EP infants discharged from 26 neonatal intensive care units during 2008-2017 were enrolled. The data from 2008 to 2012 were collected retrospectively, and from 2013 to 2017 were collected prospectively. Their hospitalization records were reviewed.
During 2008-2017, the mean gestational age (GA) was 26.68 ± 1.00 weeks and the mean birth weight (BW) was 935 ± 179 g. The overall survival rate at discharge was 52.5%. There were 321 infants (15.7%) died despite active treatment, and 654 infants (31.9%) died after medical care withdrawal. The survival rates increased with advancing GA and BW (p < 0.001). The annual survival rate improved from 36.2% in 2008 to 59.3% in 2017 (p < 0.001). EP infants discharged from hospitals in Guangzhou and Shenzhen cities had a higher survival rate than in others (p < 0.001). The survival rate of EP infants discharged from general hospitals was lower than in specialist hospitals (p < 0.001). The major complications were neonatal respiratory distress syndrome, 88.0% (1804 of 2051), bronchopulmonary dysplasia, 32.3% (374 of 1158), retinopathy of prematurity (any grade), 45.1% (504 of 1117), necrotizing enterocolitis (any stage), 10.1% (160 of 1588), intraventricular hemorrhages (any grade), 37.4% (535 of 1431), and blood culture-positive nosocomial sepsis, 15.7% (250 of 1588). The multivariate logistic regression analysis indicated that improved survival of EP infants was associated with discharged from specialist hospitals, hospitals located in high-level economic development region, increasing gestational age, increasing birth weight, antenatal steroids use and a history of premature rupture of membranes. However, twins or multiple births, Apgar ≤7 at 5 min, cervical incompetence, and decision to withdraw care were associated with decreased survival.
Our study revealed the short-term outcomes of EP infants at discharge in China. The overall survival rate was lower than the developed countries, and medical care withdrawal was a serious problem. Nonetheless, improvements in care and outcomes have been made annually.
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•K-doped GQDs were synthesized by mechanochemical reaction for the first time.•K atoms were chemically bonded into the N and O-the so-called Lewis sites of GQDs.•K induced long ...wavelength fluorescence enhancement effect was demonstrated.•K-GQDs displayed benign cytocompatibility and good cellular imaging performance.
The electron modification effects of alkaline metal on graphene and carbon nanotubes have been widely studied by numerous research groups, but never been explored on graphene quantum dots (GQDs), owing to the limitation of synthetic method. Here, we presented a dopant controllable mechanochemical procedure for potassium-doped GQDs (K-GQDs) preparation: by shifting the synthetic parameters, the doping degree of K can be effectively adjusted with little change of the crystal lateral size. Physiochemical characterizations revealed that the K+ tended to form chemical bonds with carbonyls, pyrrolic and graphic nitrogen-the so-called Lewis acid. Spectral techniques further confirmed the K dopants on the as-mentioned sites could reduce the blue fluorescence that related to the intrinsic state, but enhance the yellow and orange florescence caused by the increase of electron radiative transition rate between π*-nO2p and π*-nN2p simultaneously. Moreover, the K-GQDs displayed benign cytocompatibility and cellular fluorescence imaging performance. Herein, we propose the K+ may play a role in enhancing long wavelength florescence intensity of GQDs, which makes the K-GQDs a promising probe for bioimaging. To our knowledge, this is the first time to report the successful preparation of GQDs chemically doped by K element and reveal the long wavelength florescence enhancement (LWFE) effect of K doping. Our findings suggest that the alkaline metal doping may be an effective technique to overcome the florescence wavelength limitations of GQDs in bioimaging applications.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Based on the fact that characters of vehicle license plate are standardized, a recognition algorithm of Vehicle License Plate Characters based on non-learning-oriented method is proposed. This method ...uses some concepts such as Shape Feature Vector (SFV, for short) to describe the shape of the to be recognized characters. Each character will be evaluated with a vector and the recognition is realized by calculating the similarity of vectors. This method achieves character recognition by vector arithmetic avoiding the learning/training process often used in some algorithms, such as artificial neural network, and SVM and so on. The recognition is simplified tremendously. The feasibility of using SFV to recognize vehicle license plate characters is proven theoretically, and then, the character recognition algorithm of vehicle license plate is evaluated by simulation. The result of the simulation shows that SFV can be used as license plate character recognition. And the license plate recognition algorithm based on SFV has an accuracy rate of 97.31%. This method is a helpful attempt of character recognition based on non-learning-oriented method.
Synergistic apoptosis and ferroptosis strategy is quite promising for tumor treatment. Herein, a kind of polyacrylic acid-stabilized, carboxymethyl chitosan-coated, doxorubicin (DOX)-loaded copper ...phosphate nanoparticles (NPs) were prepared by a simple method for synergistic apoptosis and ferroptosis against tumor cells. The finally formed PAA-Cu
3
(PO
4
)
2
-DOX-CMCS (PCPDC) NPs displayed suitable hydrodynamic size (208.7 nm) and surface charge. When uptaken by tumor cells, they were degraded under acidic circumstances, releasing DOX and Cu
2+
ions. The released Cu
2+
ions reacted with glutathione (GSH) to produce Cu
+
ions and deplete GSH. Through Cu
+
ions-mediated Fenton-like reaction, H
2
O
2
can be converted to hydroxyl radical to produce lipid hydroperoxides. Furthermore, the depleted GSH down-regulated the expression of glutathione peroxidase 4 (GPX4) protein, promoting the accumulation of lipid hydroperoxides to enhance ferroptosis. The released DOX can effectively induce apoptosis in tumor cells. These developed Cu
3
(PO
4
)
2
-based nanomaterials can kill tumor cells effectively through the synergistic apoptosis and ferroptosis strategy.
Underwater noise from anthropogenic activities can have negative behavioral and physical effects on marine life, including physical changes, injuries, and death. Impact pile driving and vibratory ...pile driving are generally used for the construction of ocean-based foundations. Based on the field data under the same marine engineering and marine environment, this paper addresses the characteristics of underwater noise from impact and vibratory pile driving, their differences, and the effects of noise on populations of the large yellow croaker (
Pseudosciaena crocea
). The impact pile driving pulse had a median peak-to-peak sound pressure source level (SPL
pp
) of 244.7 dB re 1 μPa at 1 m and a median sound exposure source level (SEL
ss
) of 208.1 dB re 1 μPa
2
s at 1 m by linear regression. The waveform of vibratory pile driving appears to be continuous with a low SPL
pp
, but the cumulative SEL (SEL
cum
) in 1 min is very high, reaching 207.5 dB re 1 μPa
2
s at 1 m. The range of behavioral response for adult large yellow croaker (20–23 cm) is predicted to be 4,798 m for impact pile driving and 1,779 m for vibratory pile driving. The study provides evidence of the comparative potential effects of vibratory and impact pile driving on the large yellow croaker and reference for the conservation of croaker.
IMPORTANCE: Several respiratory support techniques are available to minimize the use of invasive mechanical ventilation (IMV) in preterm neonates. It is unknown whether noninvasive high-frequency ...oscillatory ventilation (NHFOV) is more efficacious than nasal continuous positive airway pressure (NCPAP) or nasal intermittent positive pressure ventilation (NIPPV) in preterm neonates after their first extubation. OBJECTIVE: To test the hypothesis that NHFOV is more efficacious than NCPAP or NIPPV in reducing IMV after extubation and until neonatal intensive care unit discharge among preterm neonates. DESIGN, SETTING, AND PARTICIPANTS: This multicenter, pathophysiology-based, assessor-blinded, 3-group, randomized clinical trial was conducted in 69 tertiary referral neonatal intensive care units in China, recruiting participants from December 1, 2017, to May 31, 2021. Preterm neonates who were between the gestational age of 25 weeks plus 0 days and 32 weeks plus 6 days and were ready to be extubated were randomized to receive NCPAP, NIPPV or NHFOV. Data were analyzed on an intention-to-treat basis. INTERVENTIONS: The NCPAP, NIPPV, or NHFOV treatment was initiated after the first extubation and lasted until discharge. MAIN OUTCOMES AND MEASURES: Primary outcomes were total duration of IMV, need for reintubation, and ventilator-free days. These outcomes were chosen to describe the effect of noninvasive ventilation strategy on the general need for IMV. RESULTS: A total of 1440 neonates (mean SD age at birth, 29.4 1.8 weeks; 860 boys 59.7%) were included in the trial. Duration of IMV was longer in NIPPV (mean difference, 1.2; 95% CI, 0.01-2.3 days; P = .04) and NCPAP (mean difference, 1.5 days; 95% CI, 0.3-2.7 days; P = .01) compared with NHFOV. Neonates who were treated with NCPAP needed reintubations more often than those who were treated with NIPPV (risk difference: 8.1%; 95% CI, 2.9%-13.3%; P = .003) and NHFOV (risk difference, 12.5%; 95% CI, 7.5%-17.4%; P < .001). There were fewer ventilator-free days in neonates treated with NCPAP than in those treated with NIPPV (median 25th-75th percentile difference, −3 −6 to −1 days; P = .01). There were no differences between secondary efficacy or safety outcomes, except for the use of postnatal corticosteroids (lower in NHFOV than in NCPAP group; risk difference, 7.3%; 95% CI, 2.6%-12%; P = .002), weekly weight gain (higher in NHFOV than in NCPAP group; mean difference, −0.9 g/d; 95% CI, −1.8 to 0 g/d; P = .04), and duration of study intervention (shorter in NHFOV than in NIPPV group; median 25th-75th percentile difference, −1 −3 to 0 days; P = .01). CONCLUSIONS AND RELEVANCE: Results of this trial indicated that NHFOV, if used after extubation and until discharge, slightly reduced the duration of IMV in preterm neonates, and both NHFOV and NIPPV resulted in a lower risk of reintubation than NCPAP. All 3 respiratory support techniques were equally safe for this patient population. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03181958
Objective
To explore the relationship between folic acid supplementation and the recovery rate of gestational diabetes mellitus (GDM) in women with methylenetetrahydrofolate (
MTHFR
) 677 TT ...genotypes in mid-late pregnancy.
Methods
9, 096 pregnant women were recruited with their
MTHFR
gene genotyped. 5,111 women underwent a 75-g oral glucose tolerance test (OGTT) and 2,097 were confirmed with GDM. The association between
MTHFR
genotypes and GDM risk was estimated using logistic and log-binomial regression, with age and parity set as the covariates to control their confounding effects. Further assessment of GDM risk on glucose levels was done using the ANCOVA model. As an open-label intervention study, 53 GDM patients with TT genotype were prescribed 800μg/day of folic acid as the high-dose group, while 201 GDM patients were given 400μg/day as the standard-dose group at their 24-28 weeks of pregnancy. A rate ratio (RR) of GDM recovery was estimated at each available time point for both groups. The time-to-GDM persistence events were analyzed with the Kaplan-Meier method and Cox-regression model. The trend of glucose levels over time was estimated using the linear model.
Results
MTHFR
677 TT genotype has no significant association with the glucose levels and GDM risk, with an adjusted OR of 1.105 (95% CI 0.853, 1.431; p=0.452) and an adjusted PR of 1.050 (95% CI 0.906, 1.216; p=0.518) compared to the wildtype CC group. Patients in the high-dose group (n=38; 15 drop-outs; 40.69 days (95% CI 33.22, 48.15)) recovered from GDM approximately 27 days faster than those in the standard-dose group (n=133; 68 drop-outs; 68.09 days (95% CI 63.08, 73.11)). Concomitantly, the RR of GDM recovery rose and reached 1.247 (95% CI 1.026, 1.515) at 100 days of treatment with the standard-dose group as reference.
Conclusion
High-dose folic acid supplement intake in mid-late pregnancy is associated with faster GDM relief in patients with
MTHFR
677 TT genotype compared to the standard dose, which would be served as a novel and low-cost alternative therapy for the treatment of GDM.
Chemotherapy is still regarded as the main modality for cancer treatment. However, it often suppresses the host immune system, resulting in limited therapeutic effects. It is desirable to design a ...novel chemotherapeutic agent to reduce the level of immunosuppression. Herein, we designed bovine serum albumin (BSA)-bioinspired iron oxide nanoparticles (IONPs) as a nanocarrier to load anticancer drug mitoxantrone (MTX) for enhanced chemotherapy of orthotopic breast cancer. The treatment with IONPs@BSA-MTX complexes increased CD3
+
CD4
+
and CD3
+
CD8
+
T lymphocytes more than free MTX. The complexes effectively restored the host immune system and exhibited a better anticancer efficacy than free MTX. It was worth noting that the BSA-inspired IONPs were a satisfactory contrast agent for magnetic resonance imaging of tumors and lymph nodes. Our work provides a novel strategy for enhanced chemotherapy with low levels of immunosuppression in the treatment of breast cancer and other cancers.
BSA-bioinspired iron oxide nanoparticles as a nanocarrier to load anticancer drug mitoxantrone for enhanced chemotherapy with low levels of immunosuppression.
Tumor-associated macrophages (TAMs)-mediated immunotherapy has attracted extensive attention in tumor elimination. However, the acidic tumor microenvironment (TME) severely limits the phenotype of ...TAMs to pro-tumoral M2 state, suppressing immune response efficacy against tumors. Herein, novel poly(acrylic acid) (PAA)-coated, doxorubicin (DOX)-loaded layered double hydroxide (LDH) nanosheets (NSs) were developed as deacidification agent to repolarize TAMs from pro-tumoral M2 to anti-tumoral M1 phenotype for tumor elimination through combined chemodynamic therapy and immunotherapy. When located in tumor regions, LDH-PAA@DOX NSs display good deacidification capacity to neutralize acidic TME, achieving the repolarization of TAMs to M1 phenotype and further activating CD8+ T cells. During the deacidification process, these NSs are acid-responsive and degrade to release Fe3+ and DOX. The former can be reduced to Fe2+ by intracellular glutathione, meanwhile disrupting the antioxidant defense system of tumor cells. The latter can damage tumor cells directly and further stimulate the production of hydrogen peroxide, providing abundant substrate for the Fenton reaction. Toxic hydroxyl radical is excessively produced through Fe2+-mediated Fenton reaction to cause intratumoral oxidative stress. In vivo data revealed that significant tumor elimination can be achieved under LDH-PAA@DOX treatment. This work not only provides a promising paradigm for neutralizing acidic TME using deacidification agent but also highlights the effectiveness of combined chemodynamic therapy and immunotherapy in tumor treatment.
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•A kind of deacidification agent based on LDH-PAA@DOX NSs was developed.•LDH-PAA@DOX NSs could neutralize the acidic tumor microenvironment.•LDH-PAA@DOX NSs could promote the repolarization of tumor-associated macrophages.•LDH-PAA@DOX NSs were acid-responsive and could produce hydroxyl radicals.•Tumor elimination was achieved through chemodynamic therapy and immunotherapy.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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