Evolution of Symptoms After Ustekinumab Induction Therapy in Patients With Crohn's Disease.

BACKGROUND & AIMS: Ustekinumab is an effective treatment of Crohn's disease (CD). Of interest to patients is knowing how soon symptoms may improve. We analyzed ustekinumab response dynamics from the ustekinumab CD trials. METHODS: Patients with CD received intravenous induction with ustekinumab ∼6 mg/kg (n = 458) or placebo (n = 457). Week 8 ustekinumab responders received subcutaneous ustekinumab 90 mg as the first maintenance dose or as an extended induction dose for nonresponders. Patient-reported symptom changes (stool frequency, abdominal pain, general well-being) within the first 14 days and clinical outcomes through week 44 were evaluated using the CD Activity Index. RESULTS: After ustekinumab infusion, stool frequency improvement was significantly (P < .05) greater than placebo on day 1 and for all patient-reported symptoms by day 10. In patients with no history of biologic failure or intolerance, cumulative clinical remission rates increased from 23.0% at week 3 to 55.5% at week 16 after the subcutaneous dose at week 8. Corresponding cumulative rates for patients with a history of biologic failure or intolerance increased from 12.9% to 24.1%. Neither change from baseline in CD Activity Index score nor week 8 ustekinumab pharmacokinetics were associated with week 16 response. Among all patients who received subcutaneous ustekinumab 90 mg q8w, up to 66.7% were in clinical response at week 44. CONCLUSIONS: Ustekinumab induction provided symptom relief by day 1 post-infusion. Following ustekinumab infusion and a subcutaneous 90 mg injection, clinical outcomes continued to increase through week 16 and up to week 44. Regardless of week 8 clinical status or ustekinumab pharmacokinetics, patients should receive additional treatment at week 8. CLINICALTRIALS: gov numbers, NCT01369329, NCT01369342, and NCT01369355.

Ustekinumab versus adalimumab for induction and maintenance therapy in biologic-naive patients with moderately to severely active Crohn's disease: a multicentre, randomised, double-blind, parallel-group, phase 3b trial.

BACKGROUND: Active-comparator trials are important to inform patient and physician choice. We aimed to evaluate the efficacy and safety of monotherapy with either ustekinumab or adalimumab in biologic-naive patients with moderately to severely active Crohn's disease. METHODS: We conducted a randomised, double-blind, parallel-group, active-comparator, phase 3b trial (SEAVUE) at 121 hospitals or private practices in 18 countries. We included biologic-naive patients aged 18 years or older with moderately to severely active Crohn's disease and a Crohn's Disease Activity Index (CDAI) score of 220-450, who had not responded to or were intolerant to conventional therapy (or were corticosteroid dependent) and had at least one ulcer of any size at baseline endoscopic evaluation. Eligible patients were randomly assigned (1:1; via an interactive web response system) to receive ustekinumab (approximately 6 mg/kg intravenously on day 0, then 90 mg subcutaneously once every 8 weeks) or adalimumab (160 mg on day 0, 80 mg at 2 weeks, then 40 mg once every 2 weeks, subcutaneously) through week 56. Study treatments were administered as monotherapy and without dose modifications. Patients, investigators, and study site personnel were masked to treatment group assignment. The primary endpoint was the proportion of patients who were in clinical remission (CDAI score <150) at week 52 in the intention-to-treat population (ie, all patients who were randomly assigned to a treatment group). This trial is registered with ClinicalTrials.gov, NCT03464136, and EudraCT, 2017-004209-41. FINDINGS: Between June 28, 2018, and Dec 12, 2019, 633 patients were assessed for eligibility and 386 were enrolled and randomly assigned to receive ustekinumab (n=191) or adalimumab (n=195). 29 (15%) of 191 patients in the ustekinumab group and 46 (24%) of 195 in the adalimumab group discontinued study treatment before week 52. There was no significant difference between the ustekinumab and adalimumab groups in the occurrence of the primary endpoint; at week 52, 124 (65%) of 191 patients in the ustekinumab group versus 119 (61%) of 195 in the adalimumab group were in clinical remission (between-group difference 4%, 95% CI -6 to 14; p=0·42). Safety for both groups was consistent with previous reports. Serious infections were reported in four (2%) of 191 patients in the ustekinumab group and five (3%) of 195 in the adalimumab group. No deaths occurred through week 52 of the study. INTERPRETATION: Both ustekinumab and adalimumab monotherapies were highly effective in this population of biologic-naive patients, with no difference in the primary outcome between the drugs. FUNDING: Janssen Scientific Affairs.

Ustekinumab Therapeutic Drug Monitoring-Impact on Clinical Practice: A Multicenter Cross-Sectional Observational Trial.

BACKGROUND AND AIMS: The value of ustekinumab (UST) therapeutic drug monitoring (TDM) in clinical practice remains unclear. This study examined the impact of UST TDM on clinical decision making in patients with Crohn's disease (CD). METHODS: A total of 110 consecutive UST-treated CD patients were enrolled in this multicenter, single-arm cross-sectional study. During a single study visit, clinical decisions, disease characteristics, and serum and fecal samples were obtained. The primary outcome was congruency of the actual and two hypothetical clinical decisions based on provision of UST TDM (with and without fecal calprotectin [FCP]) to participating clinicians. Decisions were compared against those of a review panel. A sub-study retrospectively measured the associations of clinical outcomes at the next follow-up visit with serum UST concentration [UST]. RESULTS: No differences in the pattern of decisions by clinicians were observed before and after provision of UST TDM (P = 1.0) or UST TDM + FCP (P = 0.86). However, 39% (TDM) and 50% (TDM + FCP) of hypothetical decisions differed from the initial decisions. The review panel's decisions differed with the addition of TDM + FCP (P = 0.0006), but not TDM alone (P = 0.16). The sub-study (n = 53) failed to detect an association between therapeutic serum [UST] at the initial study visit and clinical outcomes at the next visit. CONCLUSIONS: In consecutive CD patients treated with UST, the addition of TDM into routine clinical practice did not significantly impact clinical decisions and there was no association between short-term clinical outcomes and serum [UST]. Further studies are warranted before clinicians routinely implement UST TDM into clinical practice.

Numerical and Experimental Investigation of the Conjugate Heat Transfer for a High-Pressure Pneumatic Control Valve Assembly.

This paper uses heat transfer experiments and computational fluid dynamics (CFD) simulations to investigate the conjugate heat transfer (CHT) in a high-pressure pneumatic control valve assembly. A heat transfer test rig was constructed, and time-temperature histories of five test points placed on the valve assembly's outer surface were recorded for study validation. The Unsteady Reynolds-Averaged Navier-Stokes (URANS) CFD methods with the standard k-ε turbulence closure equations were adopted in the numerical computations. Polyhedral grids were used; time step and mesh convergence studies were conducted. Simulated and measured temperatures profile comparisons revealed a good agreement. The CHT results obtained from CFD showed huge velocity fields downstream of the valve throat and the vent hole. The airflow through the valve was icy, mainly in the supersonic flow areas. Low temperatures below 273.15 K were recorded on the internal and external walls of the valve assembly. The consistency of the measured data with the numerical results demonstrates the effectiveness of polyhedral grids in exploring the CHT using CFD methods. The local entropy production rate analysis revealed that irreversibility is mainly due to viscous dissipation. The current CHT investigation provides a potential basis for thermostress analysis and optimization.

[Cloning and functional characterization of two oxidosqualene cyclase genes from Siraitia grosvenorii].

Oxidosqualene cyclases(OSCs), belonging to a multigene family, can convert a common precursor 2,3-oxidosqualene into various types of triterpene skeletons. In this study, primers were designed according to the analysis of Siraitia grosvenorii transcriptome data, and two OSC genes SgAS1(GenBank No. QDO67189.1) and SgAS2(GenBank No. QDO67190.1) were cloned. The open reading frame(ORF) of SgAS1 was 2 262 bp, encoding 754 amino acids, and the ORF of SgAS2 was 2 289 bp, encoding 762 amino acids. Real-time quantitative PCR results demonstrated that the two SgOSCs genes showed different expression patterns in stems, leaves, and different stages of fruits. Phylogenetic analysis showed that both SgAS1 and SgAS2 were clustered with ß-amyrin synthases into a branch, but further functional characterization using yeast heterologous expression found that SgAS1 was inactive and SgAS2 could produce ß-amyrin as the sole product. Multiple sequence alignments revealed that SgAS2 had a conserved MWCYCR sequence related to ß-amyrin biosynthesis, while SgAS1 had an unusual LFCYTR sequence, for which the authors performed site-directed mutagenesis analysis of this sequence and found that tryptophan residue(W) was the key amino acid residue that affected the function of SgOSCs. In addition, the authors transformed the monofunctional ß-amyrin synthase SgAS2 into the chassis strain GH1, which was previously modified by the research group, and increased the yield of ß-amyrin to 44.05 mg·L~(-1). This study first reported the monofunctional ß-amyrin synthase SgAS2 from S. grosvenorii and conducted site-directed mutagenesis and synthetic biology investigation on it, providing a valuable resource for the directed biosynthesis of triterpenoids.

Ustekinumab as Induction and Maintenance Therapy for Crohn's Disease.

BACKGROUND: Ustekinumab, a monoclonal antibody to the p40 subunit of interleukin-12 and interleukin-23, was evaluated as an intravenous induction therapy in two populations with moderately to severely active Crohn's disease. Ustekinumab was also evaluated as subcutaneous maintenance therapy. METHODS: We randomly assigned patients to receive a single intravenous dose of ustekinumab (either 130 mg or approximately 6 mg per kilogram of body weight) or placebo in two induction trials. The UNITI-1 trial included 741 patients who met the criteria for primary or secondary nonresponse to tumor necrosis factor (TNF) antagonists or had unacceptable side effects. The UNITI-2 trial included 628 patients in whom conventional therapy failed or unacceptable side effects occurred. Patients who completed these induction trials then participated in IM-UNITI, in which the 397 patients who had a response to ustekinumab were randomly assigned to receive subcutaneous maintenance injections of 90 mg of ustekinumab (either every 8 weeks or every 12 weeks) or placebo. The primary end point for the induction trials was a clinical response at week 6 (defined as a decrease from baseline in the Crohn's Disease Activity Index [CDAI] score of ≥100 points or a CDAI score <150). The primary end point for the maintenance trial was remission at week 44 (CDAI score <150). RESULTS: The rates of response at week 6 among patients receiving intravenous ustekinumab at a dose of either 130 mg or approximately 6 mg per kilogram were significantly higher than the rates among patients receiving placebo (in UNITI-1, 34.3%, 33.7%, and 21.5%, respectively, with P≤0.003 for both comparisons with placebo; in UNITI-2, 51.7%, 55.5%, and 28.7%, respectively, with P<0.001 for both doses). In the groups receiving maintenance doses of ustekinumab every 8 weeks or every 12 weeks, 53.1% and 48.8%, respectively, were in remission at week 44, as compared with 35.9% of those receiving placebo (P=0.005 and P=0.04, respectively). Within each trial, adverse-event rates were similar among treatment groups. CONCLUSIONS: Among patients with moderately to severely active Crohn's disease, those receiving intravenous ustekinumab had a significantly higher rate of response than did those receiving placebo. Subcutaneous ustekinumab maintained remission in patients who had a clinical response to induction therapy. (Funded by Janssen Research and Development; ClinicalTrials.gov numbers, NCT01369329 , NCT01369342 , and NCT01369355 .).

Combination Therapy With Infliximab and Azathioprine Improves Infliximab Pharmacokinetic Features and Efficacy: A Post Hoc Analysis.

BACKGROUND & AIMS: Among immunosuppressive- and biologic-naïve patients with moderately-to-severely active Crohn's disease (CD), a higher proportion of those treated with the combination of infliximab and azathioprine achieved corticosteroid-free remission at week 26 (CSFR26) than those given infliximab monotherapy; patients given the combination therapy also had higher serum concentrations of infliximab. Enhanced benefit of combination therapy may occur through synergistic modes of action or the influence of azathioprine on infliximab pharmacokinetics. METHODS: We analyzed data from 206 patients from whom week 30 serum samples were available: 97 received infliximab monotherapy (5 mg/kg, n = 97) and 109 received combination therapy (2.5 mg/kg/day; n = 109). Proportions of patients achieving CSFR26 and mucosal healing (absence of ulcers) at week 26 were calculated for each quartile of serum concentrations of infliximab, and exposure-response relationships were compared. RESULTS: Within quartiles of serum concentrations of infliximab, CSFR26 did not differ significantly between patients who received combination therapy vs monotherapy. However, among patients in the lowest quartile of serum concentration of infliximab, twice as many patients who received infliximab monotherapy achieved CSFR26 vs combination therapy. Anti-drug antibodies were detected only in the lowest quartile of serum concentrations of infliximab-in 35.9% of patients given monotherapy and 8.3% of patients given combination therapy. CONCLUSION: Among patients with CD and similar serum concentrations of infliximab, combination therapy with azathioprine was not significantly more effective than infliximab monotherapy. Combination therapy with azathioprine appears to improve efficacy by increasing pharmacokinetic features of infliximab. ClinicalTrials.gov, NCT00094458.

Pharmacokinetics and Exposure Response Relationships of Ustekinumab in Patients With Crohn's Disease.

BACKGROUND & AIMS: Ustekinumab is a monoclonal antibody that binds with high affinity to the p40 subunit of human interleukin 12 (IL12 and IL23) that has been approved for treatment of patients with moderate to severe Crohn's disease (CD). However, there are few data on its pharmacokinetic properties or the relationship between drug exposure levels and patient response. We collected data from 2 Phase 3 induction studies and 1 maintenance study to determine ustekinumab's pharmacokinetic features, relationship between exposure and response, and optimal serum concentrations for efficacy. METHODS: We collected data on serum concentrations of ustekinumab and efficacy from induction studies of patients with moderate to severe CD given ustekinumab for 8 weeks following a single intravenous dose (either 130 mg or approximately 6 mg/kg). We collected the same data from a maintenance study of patients with a response to ustekinumab in the induction study who then received subcutaneous injections (90 mg) every 8 or 12 weeks for 44 weeks. At week 44 of the maintenance study (52 weeks after treatment began), patients were evaluated for the primary endpoint of clinical remission (defined as a CD activity index score below 150 points), endoscopic markers of efficacy, and serum level of C-reactive protein. Ustekinumab concentration data were categorized into quartiles and relationships between exposure and response were assessed. Optimal concentration cutoff values were evaluated using receiver operating characteristic curve analysis. RESULTS: Serum concentrations of ustekinumab over time were proportional to dose and did not differ significantly between the induction studies. In the maintenance study, ustekinumab concentration reached the steady state by the second maintenance dose; the median trough concentration was approximately threefold higher in patients given ustekinumab at 8-week intervals compared with 12-week intervals. Ustekinumab serum concentrations associated with rates of clinical remission and endoscopic efficacy endpoints, correlated inversely with level of C-reactive protein, and did not associate with use of immunomodulators. Trough concentrations of ustekinumab of 0.8 (or even up to 1.4 µg/mL) or greater were associated with maintenance of clinical remission in a higher proportion of patients than patients with lower trough concentrations. CONCLUSIONS: In an analysis of data from Phase 3 studies of patients with moderate to severe CD, we found serum concentrations of ustekinumab to be proportional to dose and associate with treatment efficacy. Concentrations of ustekinumab did not seem to be affected by cotreatment with immunomodulators. Clinicaltrials.gov no. NCT01369329 (UNITI 1), NCT01369342 (UNITI 2), and NCT01369355 (IM-UNITI).

Fluorescently probing site-specific and self-catalyzed DNA depurination.

Depurination occurs via hydrolysis of the purine-deoxyribose glycosyl bond and causes nucleic acid damage. In particular, the DNA sequences that can undergo a self-catalyzed depurination (SCD) will cause a great uncertainty in duplicating, separating, purifying, and storing the DNA samples. Therefore, there is a great demand to develop a rapid detection method for SCD events. Herein, the use of a convenient fluorescence method to follow the site-specific SCD was demonstrated. We found that the resultant apurine site (AP site) from depurination can be selectively recognized by a fluorescent probe of palmatine (PAL) with a turn-on fluorescence response. The dependence of SCD on the bases of the depurination site, pH, metal ions, and time shows that our method can be used to rapidly evaluate the depurination process. Furthermore, the depurination process can be photo-switched using a photoacid as an external initiator. Our work will find wide applications in preliminarily identifying the DNA depurination.

Assessing the brain 'on the line': An ecologically-valid assessment of the impact of repetitive assembly line work on hemodynamic response and fine motor control using fNIRS.

To investigate neural correlates of repetitive assembly tasks in ecologically-valid empirical settings, this study measured bilateral prefrontal (PFC) and motor activations when participants performed a carburetor assembly task using functional near-infrared spectroscopy (fNIRS). Participants worked for one hour at a typical (low-) pace and at an accelerated high-pace. Before and after the task, a test was conducted to assess motion stability and fine motor control. The behavioral data revealed decreased motion stability after the assembly work in both conditions, with a significantly higher reduction after the high-pace task. The fNIRS data also revealed reduced activations in bilateral prefrontal and motor regions in both conditions over time. However, the low-pace task led to significantly greater activity decreases compared with the high-pace. Activity decrease in prefrontal and motor regions within the low pace also significantly related to minimal motion stability impairment, suggesting that the brain activation decreases in this and, potentially, findings of higher alpha in past repetitive-task studies using EEG, may be a result of not fatigue but worker adaptation or increasing efficiency.

Supramolecularly Multicolor DNA Decoding Using an Indicator Competition Assay.

Relative to the individual intensity-dependent strategy, the multicolor fluorescence sensor has promise to achieve a high signaling contrast. In this work, we develop a cucurbituril-based supramolecular and multicolor DNA recognition rationale via indicator competition assay (ICA). Alkaloids of coptisine (COP) and palmatine (PAL) are identified as the proof-of-principle indicators with a lighting-up fluorescence upon supramolecular complexation to cucurbit[7]uril (CB[7]). With an introduced abasic site (AP site) as the contestant, DNAs having pyrimidines opposite this site can compete for COP with CB[7] to bring an emission color change from green to yellow brown, while those having purines opposite the AP site do not compete for COP and still have the green emission, indicative of a high selectivity for the multicolor nucleotide transversion recognition. However, because of the relatively weaker binding of PAL with CB[7], the AP site-containing DNA can take away PAL from its CB[7] complex and resultantly bring a blue-to-green emission color change independent of the AP site-opposite nucleotide identity, dissimilar to the remaining blue color for the fully matched DNA without the AP site, suggesting a preferable strategy for the AP site biomarker detection. Our method demonstrates a new way to develop an ICA-based multicolor DNA sensor with the supramolecular cucurbituril complexation to ensure a highly selective performance.

G-Quadruplex DNA with an Apurinic Site as a Soft Molecularly Imprinted Sensing Platform.

Molecularly imprinted polymers (MIPs) provide versatile sensor platforms to recognize targets by shape complementarity. However, the rigid structure of the classic MIPs compromises the signal transduction with necessary polymer and target modifications. Herein, we tried to use a flexible DNA that has a perfectly structured folding as the soft molecularly imprinted polymer (SMIP) for a straightforward sensor. As a proof of concept, the guanosine SMIP recognition was achieved by removal of a guanosine from a G-quadruplex-forming sequence (G4). The G4 folding structure with such an apurinic site (AP site) provides a well-defined MIP binding accommodation for guanosine according to the shape complementarity. The guanosine binding at the AP site subsequently leads to a conformation change suitable for remote readout using a G4-specific fluorescent ligand. The G4 sequence and AP site position were optimized for this SMIP behavior. Due to the G4 compact structure and the remaining hydrogen bonding pattern, nucleosides other than guanosine and negatively charged nucleotides exhibit no binding with the AP site, suggesting a high selectivity in the SMIP recognition. The proposed rationale was then convinced by the alkaline phosphatase-catalyzed GMP hydrolysis. Our work will inspire more interest in exploring nucleic acids as the SMIP frameworks due to their variant conformations and well-established molecular engineering.

Structuring polarity-inverted TBA to G-quadruplex for selective recognition of planarity of natural isoquinoline alkaloids.

Efficient structuring of DNA by small molecules is very crucial in developing DNA-based novel switches with an ideal performance. In this work, we found that inverting only the polarity of the 3' terminal guanine of the thrombin-binding aptamer (3iTBA) totally eradicates the original TBA G-quadruplex (G4) structure in K+. The unstructured 3iTBA can be further refolded upon specifically interacting with small molecules of natural isoquinoline alkaloids (IAs) due to their fruitful binding patterns with variant nucleic acid structures. We identified that 3iTBA can serve as a topology selector for planar IAs. Nitidine (NIT), owing to the planar aromatic ring and coplanar substituents, is the most efficient to restructure the 3iTBA random coil toward the anti-parallel G4 conformation. However, common metal ions can't realize this structuring. The topology selector competency of 3iTBA toward IAs' planarity can be visualized using gold nanoparticles (AuNPs) as the chromogenic readout. Our work expands the G4 repertoire by exploring the polarity inversion regulation and provides a new approach to switch nucleic acid structures toward a small molecule structure-sensitive sensor.

Target-switched triplex nanotweezer and synergic fluorophore translocation for highly selective melamine assay.

This paper describes a triplex DNA nanotweezer to specifically capture melamine (MEL). The triplex-forming oligonucleotide (TFO) arm can be switched from the open state to the closed state once MEL binds to the abasic site (AP site) in duplex via the bifacial hydrogen bonding with thymines. Following this nanotweezer operation, the AP site-bound fluorophore is translocated to the terminal triplet to subsequently light up the nanotweezer. The TFO arm is found to be pivotal for permitting the AP site binding. The synergic processes of target competition and fluorophore translocation support a high selectivity for the MEL assay even against the inherent adenosine and the MEL hydrolysis products. Chelerythrine is employed as the fluorescent probe. The detection limit of MEL was estimated to be about 140 nM assuming a signal-to-noise ratio of 3. It was applied to the determination of MEL in spiked milk samples without any separation procedure. Conceivably, this method opens a new avenue towards highly selective triplex-based sensors by making use of other commercially available DNA modifications for recognizing other analytes. Graphical abstract Schematic presentation of a triplex nanotweezer with an open-to-close conversion upon the abasic site binding of melamine. The assay is based on a synergic fluorophore translocation. The corresponding duplex otherwise shows no binding with melamine. Chelerythrine (CHE) with a yellow-green emission peaking at 544 nm is employed as the fluorescent probe.

Ustekinumab induction and maintenance therapy in refractory Crohn's disease.

BACKGROUND: In patients with Crohn's disease, the efficacy of ustekinumab, a human monoclonal antibody against interleukin-12 and interleukin-23, is unknown. METHODS: We evaluated ustekinumab in adults with moderate-to-severe Crohn's disease that was resistant to anti-tumor necrosis factor (TNF) treatment. During induction, 526 patients were randomly assigned to receive intravenous ustekinumab (at a dose of 1, 3, or 6 mg per kilogram of body weight) or placebo at week 0. During the maintenance phase, 145 patients who had a response to ustekinumab at 6 weeks underwent a second randomization to receive subcutaneous injections of ustekinumab (90 mg) or placebo at weeks 8 and 16. The primary end point was a clinical response at 6 weeks. RESULTS: The proportions of patients who reached the primary end point were 36.6%, 34.1%, and 39.7% for 1, 3, and 6 mg of ustekinumab per kilogram, respectively, as compared with 23.5% for placebo (P=0.005 for the comparison with the 6-mg group). The rate of clinical remission with the 6-mg dose did not differ significantly from the rate with placebo at 6 weeks. Maintenance therapy with ustekinumab, as compared with placebo, resulted in significantly increased rates of clinical remission (41.7% vs. 27.4%, P=0.03) and response (69.4% vs. 42.5%, P<0.001) at 22 weeks. Serious infections occurred in 7 patients (6 receiving ustekinumab) during induction and 11 patients (4 receiving ustekinumab) during maintenance. Basal-cell carcinoma developed in 1 patient receiving ustekinumab. CONCLUSIONS: Patients with moderate-to-severe Crohn's disease that was resistant to TNF antagonists had an increased rate of response to induction with ustekinumab, as compared with placebo. Patients with an initial response to ustekinumab had significantly increased rates of response and remission with ustekinumab as maintenance therapy. (Funded by Janssen Research and Development; CERTIFI ClinicalTrials.gov number, NCT00771667.).

Construction of a high-efficiency GjCCD4a mutant and its application for de novo biosynthesis of five crocins in Escherichia coli.

Crocins are bioactive natural products that rarely exist in plants. High costs and resource shortage severely limit its development and application. Synthetic biology studies on crocins are of considerable global interest. However, the lack of high-efficiency genetic tools and complex cascade biocatalytic systems have substantially hindered progress in crocin biosynthesis-related research. Based on mutagenesis, a high-efficiency GjCCD4a mutant (N212m) was constructed with a catalytic efficiency that was 25.08-fold higher than that of the wild-type. Solubilized GjCCD4a was expressed via fusion with an MBP tag. Moreover, N212m and ten other genes were introduced into Escherichia coli for the de novo biosynthesis of five crocins. The engineered E57 strain produced crocins III and V with a total yield of 11.50 mg/L, and the E579 strain produced crocins I-V with a total output of 8.43 mg/L at shake-flask level. This study identified a marvelous genetic element (N212m) for crocin biosynthesis and achieved its de novo biosynthesis in E. coli using glucose. This study provides a reference for the large-scale production of five crocins using E. coli cell factories.

Application of third-generation sequencing to herbal genomics.

There is a long history of traditional medicine use. However, little genetic information is available for the plants used in traditional medicine, which limits the exploitation of these natural resources. Third-generation sequencing (TGS) techniques have made it possible to gather invaluable genetic information and develop herbal genomics. In this review, we introduce two main TGS techniques, PacBio SMRT technology and Oxford Nanopore technology, and compare the two techniques against Illumina, the predominant next-generation sequencing technique. In addition, we summarize the nuclear and organelle genome assemblies of commonly used medicinal plants, choose several examples from genomics, transcriptomics, and molecular identification studies to dissect the specific processes and summarize the advantages and disadvantages of the two TGS techniques when applied to medicinal organisms. Finally, we describe how we expect that TGS techniques will be widely utilized to assemble telomere-to-telomere (T2T) genomes and in epigenomics research involving medicinal plants.

Measurement of the mass-flow-rate characterization parameters of high-pressure pneumatic servo slide valves.

The mass-flow-rate characteristics of high-pressure pneumatic servo valves (HPSVs) have an important effect on the dynamic performance of high-pressure servo systems. However, these characteristics are difficult to obtain by theoretical calculations and flowmeter measurements owing to the compressibility of high-pressure gas. In this paper, a new measurement method of the mass-flow-rate characterization parameters of HPSVs is proposed based on the principle of the series connection sonic discharge of valve orifices. The effective cross-sectional area and critical pressure ratio of the servo valve orifices can be accurately and efficiently determined by connecting two valve orifices in series and exchanging the flow sequence of the two valve orifices. The two assumptions including the sonic and adiabatic discharge of the proposed measurement method were verified. A comparison between the test and simulation data showed that the accuracy of the measured effective cross-sectional area and critical pressure ratio of the HPSV was high. The measured critical pressure ratio ranged from 0.46 to 0.50, and the flow coefficient represented by the effective cross-sectional area variation decreased with increasing valve opening. These findings have general implications for the accurate design, analysis, and control of high-pressure pneumatic servo systems.

A Fluorescently Ratiometric Natural Probe for Selective Detection of Sulfur Dioxide Derivative and Host-Guest Supramolecular Regulation.

Natural sanguinarine (SG) was first used as a fluorescent probe to develop a novel ratiometric sensor for selective HSO3- detection. The nucleophilic addition reaction of HSO3- occurs at the C=N+ group of SG, and subsequent breakage of the conjugated π cycle leads to a decrease in the SG iminium fluorescence that is accompanied by an increase in the alkanolamine fluorescence. Therefore, a ratiometric fluorescence method with a large wavelength shift can be established for HSO3- detection. Furthermore, cucurbit[8]uril was used as an efficient host to encapsulate SG for an improved selectivity for HSO3- detection over H2S. Our method benefits include little interference from other common anions and cations for HSO3- detection, suggesting a promising application in real sample analysis. Besides sensor development, the interaction of the natural SG with HSO3- was first demonstrated in this work to further get an insight into SG's pharmacology.

Multicolorfully probing intramolecular G-Quadruplex tandem interface.

A long guanine-rich oliogonucleotide sequence can form multiple G-quadruplex (G4) tandem individuals in a single molecule with internal G4-G4 (inG4-G4) interfaces. The interface can exist at the stacked (s-inG4-G4) or unstacked (us-inG4-G4) state, dependent of the G4 conformation and environment. Because of the vital bioactivity of the G4 interface state, there is a great demand for developing a reliable multicolor fluorescence method to identify the interface state using a fluorophore that can emit at the individual wavelength for a specific interface. Herein, we found that a porphyrin with four dihydroxyphenyl substituents (OH2PP) can multicolorfully recognize the s-inG4-G4 dimer interface against the us-inG4-G4 dimer one. The s-inG4-G4 dimer cause significant red shifts in the excitation and emission bands of OH2PP in contrast to the us-inG4-G4 dimer and G4 monomers. OH2PP adopts a 1:1 binding mode with the s-inG4-G4 dimer, whereas a 2:1 binding mode occurs to the us-inG4-G4 dimer. The limit of detection (LOD) for the s-inG4-G4 structure is about tens of nM level. The observed binding dependence of OH2PP on the linker length between the G4 individuals suggests the interface binding with the s-inG4-G4 dimer. Deformation of the porphyrin macrocycle within the s-inG4-G4 interface confinement most likely contributes to the multicolorful response with the hyperporphyrin effect. Our work demonstrates that OH2PP is a promising fluorophore to fluorescently recognize the G4 multimer with an ideal interface-sensitive multicolor response.