Predicting survival in patients with myelodysplastic/myeloproliferative neoplasms with SF3B1 mutation and thrombocytosis.

We investigated data from 180 consecutive patients with myelodysplastic/myeloproliferative neoplasms with SF3B1 mutation and thrombocytosis (MDS/MPN-SF3B1-T) who were diagnosed according to the 2022 World Health Organization (WHO) classification of myeloid neoplasms to identify covariates associated with survival. At a median follow-up of 48 months (95% confidence interval [CI] 35-61 months), the median survival was 69 months (95% CI 59-79 months). Patients with bone marrow ring sideroblasts (RS) < 15% had shorter median overall survival (OS) than did those with bone marrow RS ≥ 15% (41 months [95% CI 32-50 months] versus 76 months [95% CI 59-93 months]; P < 0.001). According to the univariable analyses of OS, age ≥ 65 years (P < 0.001), hemoglobin concentration (Hb) < 80 g/L (P = 0.090), platelet count (PLT) ≥ 800 × 10E + 9/L (P = 0.087), bone marrow RS < 15% (P < 0.001), the Revised International Prognostic Scoring System (IPSS-R) cytogenetic category intermediate/poor/very poor (P = 0.005), SETBP1 mutation (P = 0.061) and SRSF2 mutation (P < 0.001) were associated with poor survival. Based on variables selected from univariable analyses, two separate survival prediction models, a clinical survival model, and a clinical-molecular survival model, were developed using multivariable analyses with the minimum value of the Akaike information criterion (AIC) to specifically predict outcomes in patients with MDS/MPN-SF3B1-T according to the 2022 WHO classification.

IPSS-M has greater survival predictive accuracy compared with IPSS-R in persons ≥ 60 years with myelodysplastic syndromes.

There are considerable new data on mutation topography in persons with myelodysplastic syndromes (MDS). These data have been used to update conventional risk models such as the Revised International Prognostic Scoring System (IPSS-R). Whether the molecular IPSS (IPSS-M) which includes these data improves survival prediction accuracy is untested. To answer this question, we compared survival prediction accuracies of the IPSS-R and IPSS-M in 852 consecutive subjects with de novo MDS. Concordance statistics (C-statistics) of the IPSS-R and IPSS-M in the entire cohort were similar, 0.67 (95% Confidence Interval [CI] 0.64, 0.71) and 0.68 (0.64, 0.71). Average numbers of mutations and of IPSS-M related mutations were greater in persons ≥ 60 years (2.0 [Interquartile Range [IQR], 1, 3] vs. 1.6 [0, 2], P = 0.003; 1.6 [0, 2] vs. 1.3 [0, 2], P = 0.006). Subjects ≥ 60 years had a higher incidence of mutations in RUNX1, TP53, TET2, SRSF2, DNMT3A, STAG2, EZH2 and DDX41. In contrast, mutations in U2AF1 were more common in persons < 60 years. Next we tested survival prediction accuracy based on age < or ≥ 60 years. C-statistics of the IPSS-R and IPSS-M in subjects ≥ 60 years were 0.66 (0.61, 0.71) and 0.69 (0.64, 0.73) whereas in subjects < 60 years they were 0.67 (0.61, 0.72) and 0.65 (0.59, 0.71). These data indicate an advantage for the IPSS-M over the IPSS-R in subjects ≥ 60 years but not in those < 60 years probably because of a great frequency of mutations correlated with survival in those ≥ 60 years.

Ultra-narrow-linewidth DFB laser array based on dual-cavity feedback.

Herein, we propose a structure to simultaneously compress the distributed feedback (DFB) laser array's linewidth. The proposed structure is meticulously designed to ensure single longitudinal mode operation via the interference phenomenon between the laser's primary cavity and the dual-cavity feedback. Given the weak feedback effect for each wavelength in the laser array, the proposed structure could realize the intense compression of the laser linewidths. The study results show that the side-mode suppression ratios of each DFB laser are over 40 dB, and the linewidths have been compressed from 3 MHz to ∼800 Hz. Thus, we believe the idea of an overall compression linewidth scheme in the present study can be adopted for integrated laser arrays.

Nitrogen doped graphene quantum dots as a fluorescent probe for mercury(II) ions.

A highly selective fluorescent probe for Hg2+ is reported. It consists of nitrogen doped graphene quantum dots (NGQDs) that are nearly spherical in shape, have an average diameter of 2.7 nm and excitation-independent emission. The blue fluorescence of the NGQDs (with maximum excitation/emission at 378/447 nm) is quenched by Hg2+ due to both dynamic and static quenching. The probe has a wide detection range (2.5 µM - 800 µM) and a limit of detection of 2.5 µM. The dynamic and static quenching constants are 417 M-1 and 63500 M-1, respectively. The probe was used to quantfy Hg2+ in spiked real water samples with satisfactory results. Graphical abstract ᅟ.

Optically controlled tunable ultra-narrow linewidth fiber laser with Rayleigh backscattering and saturable absorption ring.

We propose an optically controlled tunable ultra-narrow linewidth fiber laser assisted with the mode selection induced by a saturable absorption interference ring and linewidth narrowing of fiber Rayleigh backscattering (RBS). The interference ring serves as an artificial narrow-band filter, which conduces to the laser operating at a single-frequency state. To realize narrower linewidths, additional single-mode fiber is utilized to accumulate a weak RBS feedback. On basis of inherent wavelength universality of this linewidth-narrowing mechanism, an all-optical technique is employed to enable linear and stable tunability of the laser. Cooperating with a micro-fiber Bragg grating covered by graphene, the lasing wavelength is tuned precisely and reversibly with a sensitivity of 12.4 pm/mW and a linear fitting R2 over 0.997 by changing the power of a controlling beam. During a stability test with the controlling pump power fixed, the long-term free-running power fluctuation is less than 0.5%. The Output laser linewidth is compressed to be ~200 Hz, which is also confirmed by the descending frequency noise spectrum.

Graphene-based all-optical multi-parameter regulations for an ultrafast fiber laser.

Ultrafast lasers with tunable capabilities of pulse duration and spectrum have widespread applications in telecommunication, spectroscopy, and nonlinear optical bio-imaging. However, traditional mechanical and electrical tuning methods are still challenging for precise and stable controlling. Based on graphene's photo-thermal effect, we tune the bandwidths and wavelengths of chirped fiber Bragg gratings with flexible graphene-coating approaches. By inserting the fabricated devices into an ultrafast fiber laser cavity, durations and wavelengths of the generated pulses can be all-optically tuned with sensitivities of 470 fs/mW and 2.9 pm/mW, separately. Such an optical-controlled method provides a compact and precise way to regulate various laser properties.

Tens of hertz narrow-linewidth laser based on stimulated Brillouin and Rayleigh scattering.

We proposed and demonstrated a linewidth compression method of a laser based on stimulated Brillouin scattering (SBS) and a Rayleigh backscattering structure (RBS). The relationship between the output SBS laser linewidth and the input pump linewidth was studied theoretically and experimentally. It is shown that the narrower linewidth of the pump laser leads to the narrower bandwidth of the SBS gain and, finally, the bandwidth of the SBS will tend to its intrinsic value as the linewidth of a pump laser narrower than 10 kHz; then the linewidth of an SBS fiber ring laser would tend to 200 Hz. In order to further reduce its linewidth with low cost, RBS and a simple dual-cavity feedback structure were added and, finally, a ∼75 Hz narrow-linewidth laser with a side-mode suppression ratio of 70 dB was obtained.

Dual-cavity feedback assisted DFB narrow linewidth laser.

Single longitudinal mode (SLM) distributed feedback (DFB) lasers with a linewidth lower than a few kHz find applications in many coherent detection systems. In this paper, we proposed and experimentally demonstrated a novel method to compress the linewidth of a SLM DFB laser by utilizing a dual-cavity feedback structure (DCFS). The DCFS first provides optical self-injection feedback to compress the laser linewidth, and then the two feedback lengths are carefully optimized to achieve SLM output via the Vernier principle and the suppression of modes overlapping between two cavities. The linewidthes of 1 MHz and 200 kHz were successfully compressed to ~2.7 and 1.5 kHz with a side mode suppression ratio of 38 and 45 dB, respectively. The stability of the DCFS output power can be controlled within ~0.21%. Our method provides a simple, effective, low cost way to achieve DFB linewidth compression, which will greatly improve the performance of coherent detection systems using DFB laser as sources.

A sensitive immunochromatographic assay using colloidal gold-antibody probe for rapid detection of fumonisin B1 in corn.

A sensitive immunochromatographic assay (ICA) using a colloidal gold-antibody probe for the rapid detection of fumonisin B1 (FB1) in corn samples was developed. The colour density of the test line correlated with the concentration of FB1 in the range 2-40 ng ml(-1) by the assay, and the detection limit for FB1 was 2 ng ml(-1). The linear range for FB1 was 50-1000 µg kg(-1), and the visual limit detection of the test was 1000 µg kg(-1) in corn samples. The ICA to detect FB1 is sensitive, specific and rapid. Specific anti-FB1 monoclonal antibody (mAb) and FB1-ovalbumin (FB1-OVA) conjugate antigen were prepared. FB1 mAb, labelled with colloidal gold, was used as the probe on the immunochromatographic strip. FB1-OVA and goat-anti-mouse IgG were coated onto a nitrocellulose (NC) membrane as test lines and control lines, respectively. FB1 in samples will competitively combines the FB1 mAb with the FB1-OVA in an NC membrane and the results are directly observed by the colour of the detection and quality control lines. The concentrations of FB1 mAb labelled with colloidal gold, detecting antigen and goat anti-mouse IgG, were optimised. The results indicate that the test strip is specific for FB1, with no cross-reactivity to other toxins. The strip assay for FB1 was simple, only needing one step without complicated assay performance and expensive equipment, and the total time for visual evaluation was less than 10 min. A survey of 24 corn samples from Hefei, China, was performed with the test strip and HPLC, and the detection results showed that the developed ICA and the HPLC were in excellent agreement. Hence, the developed ICA can be used as a method for rapid detection of FB1 in corn samples.

Mutational and structural characteristics of four novel heterozygous C-propeptide mutations in the proα1(I) collagen gene in Chinese osteogenesis imperfecta patients.

OBJECTIVE: Osteogenesis imperfecta (OI) with C-propeptide mutations in proα1(I) collagen gene are rarely reported. We report four novel C-propeptide mutations in COL1A1 gene from Chinese OI patients. METHODS: Clinical characteristics and radiographic findings were described for four OI patients with C-propeptide mutations in proα1(I) collagen gene. Mutations were identified by traditional DNA sequencing based on PCR. The locations of mutations were mapped, and in silico prediction was conducted to analyse their effects on protein structure. Histology studies of skin, bone and muscle tissues were performed. RESULTS: All four C-propeptide heterozygous mutations identified were in the COL1A1 gene. Heterozygous mutation of c.4021C>T (p.Q1341X) disrupted the chain recognition sequences and was found in patients with type IV OI. Mutations of c.3893C>A (p.T1298N) and c.3897C>A (p.C1299X) impeded the formation of disulphide bonds and were associated with type IV OI phenotype. Missense mutation of c.3835A>C (p.N1279H) disrupted Ca(2+) binding and led to a severe type III OI phenotype. In silico programs predicted damaging effects for the patients with type III OI and the creation of an exonic splicing enhancer hexamer sequence for the type IV patients. Expansion of the bone marrow cavity and disorganization of osteocyte alignment was evident in bone specimens; and muscle atrophy and enlargement of intramuscular connective tissue were found in muscle specimens. CONCLUSIONS: Four novel C-propeptide mutations in proα1(I) collagen gene were identified in Chinese OI patients, and their clinical severity ranged from moderate type IV to severe type III. In silico prediction of the mutation effect and histological characteristics of tissue specimens was in accordance with the OI phenotypes.

Lack of association between NCAM1 and early onset schizophrenia in a family based study in Shandong peninsula of China.

The neural cell adhesion molecule (NCAM1) gene plays important roles in cellular migration, synaptic integrity and neurodevelopment. Multiple NCAM1 proteins are differentially altered in schizophrenia (SZ). A whole genome association study was first carried out on Affymetrix genome-wide human single-nucleotide polymorphism (SNP) Array 6.0 and two pooled DNA samples consisting of 89 early onset SZ (EOS) cases and 1,000 controls. Association between rs10891495 and EOS was detected (χ(2) = 2 3.66, P = 1.15E-06). The position of this SNP is just within the NCAM1 gene. Since several previous studies reported that NCAM1 was a candidate gene for SZ, we further performed a family based association study and genotyped six SNPs (rs10891495, rs1245133, rs1821693, rs686050, rs12794326, rs674246) within NCAM1 gene in 100 EOS nuclear families. We found no evidence for association with SZ status either for SNP or for haplotype. Therefore, the NCAM1 gene is unlikely to play a major role in the etiology of early-onset SZ in the Chinese population.