Autonomous closed-loop mechanistic investigation of molecular electrochemistry via automation

Electrochemical research often requires stringent combinations of experimental parameters that are demanding to manually locate. Recent advances in automated instrumentation and machine-learning algorithms unlock the possibility for accelerated studies of electrochemical fundamentals via high-throughput, online decision-making. Here we report an autonomous electrochemical platform that implements an adaptive, closed-loop workflow for mechanistic investigation of molecular electrochemistry. As a proof-of-concept, this platform autonomously identifies and investigates an EC mechanism, an interfacial electron transfer (E step) followed by a solution reaction (C step), for cobalt tetraphenylporphyrin exposed to a library of organohalide electrophiles. The generally applicable workflow accurately discerns the EC mechanism's presence amid negative controls and outliers, adaptively designs desired experimental conditions, and quantitatively extracts kinetic information of the C step spanning over 7 orders of magnitude, from which mechanistic insights into oxidative addition pathways are gained. This work opens opportunities for autonomous mechanistic discoveries in self-driving electrochemistry laboratories without manual intervention.

Long-Term Outcomes Following Fairly Brief Androgen Suppression and Stereotactic Radiation Therapy in High-Risk Prostate Cancer: Update from the FASTR/FASTR-2 Trials

PURPOSE/OBJECTIVE(S)

There has been emerging interest in the role of ultra-hypofractionated radiotherapy for high-risk prostate cancer, especially given its low α/β ratio. However, there is limited data on the long-term outcomes of this treatment strategy. The FASTR and FASTR-2 clinical trials were designed to assess the tolerability of stereotactic ablative body radiotherapy (SABR) in high-risk prostate cancer. FASTR was discontinued early due to unacceptable acute toxicity, whereas the acute toxicities in FASTR-2 were minimal. Herein, the long-term results from these trials are reported.

MATERIALS/METHODS

Eligible patients had at least 1 high-risk feature as per the National Comprehensive Cancer Network criteria for high-risk prostate cancer, no evidence of metastatic disease, and either a score of 3+ on the Vulnerable Elderly Scale or declined standard therapy. A total of 19 patients from a single institution were enrolled on FASTR between 2011 and 2015. They received 40 Gy to the prostate and 25 Gy to the pelvic lymph nodes in 5 fractions delivered once weekly for 5 weeks, along with 1 year of androgen deprivation therapy (ADT). The excessive acute toxicity in FASTR prompted several modifications in FASTR-2, including the omission of nodal irradiation. A total of 30 patients from the same institution were enrolled on FASTR-2 between 2015 and 2017. They received 35 Gy to the prostate alone in 5 fractions delivered once weekly for 5 weeks, along with 18 months of ADT.

RESULTS

A total of 44 patients were eligible for analysis, 16 from FASTR and 28 from FASTR-2. Most patients were >70 years old (77%). High-risk features included Gleason score ≥8 (46%), T3-T4 disease (27%) and baseline PSA >20 (50%). With a median follow-up of 6.4 years, the cumulative incidence of grade ≥3 genitourinary/gastrointestinal toxicity was 50% among FASTR patients and 7% among FASTR-2 patients. At 5 years, the combined rates of biochemical failure-free survival, freedom from distant metastases, prostate cancer-specific survival and overall survival were 72%, 90%, 92% and 83%, respectively. A total of 12 patients (27%) required further treatment. No significant differences in clinical outcomes were noted between the FASTR and FASTR-2 cohorts.

CONCLUSION

SABR for high-risk prostate cancer is an attractive option for reducing treatment burden. Clinical outcomes and toxicity with the FASTR-2 protocol were comparable to conventionally-fractionated radiotherapy plus ADT. Larger prospective, randomized trials exploring the role of SABR with ADT in high-risk disease are necessary to better understand the efficacy and tolerability of this approach.

The Role of Radiotherapy in Patients with Refractory Hodgkin Lymphoma after Brentuximab Vedotin and -/or Immune Checkpoint Inhibitors

PURPOSE/OBJECTIVE(S)

Brentuximab vedotin (BV) and immune checkpoint inhibitors (ICIs) had important roles in the treatment of relapse or refractory (R/R) Hodgkin lymphoma (HL). Treatment of refractory disease after BV and -/or ICIs remains a challenge. This study was conducted to evaluate the efficacy and safety of radiotherapy for R/R HL after failure to BV or ICIs.

MATERIALS/METHODS

We retrospectively analyzed patients in two institutions with R/R HL who had failed after first-line therapy, and were refractory to BV or ICIs, and received radiotherapy (RT) thereafter. The overall response rate (ORR), duration of response (DOR), progression-free survival (PFS) and overall survival (OS) were analyzed.

RESULTS

A total of 19 patients were enrolled. First-line systemic therapy consisted of ABVD (84.2%), AVD + ICIs (10.5%) and BEACOPP (5.3%), respectively. After first-line therapy, 15 patients (78.9%) were refractory, and 4 patients (21.1%) relapsed. After diagnosis of R/R HL, 8 patients (42.1%) received BV, and 17 patients (89.5%) received ICIs. RT was delivered in all 19 patients who failed after BV or ICIs. In 16 efficacy-evaluable patients, the ORR and CR rate were 100% and 100%. The median DOR was 17.2 months (range, 7.9 to 46.7 months). 3 patients progressed at outside of the radiation field. The in-field-response rate was 100%. The 12-month PFS and OS were 84.4% and 100%, respectively. No patients were reported with sever adverse events.

CONCLUSION

This study concluded that radiotherapy was effective and safe for refractory HL after BV or ICIs. Further prospective studies were warranted.

Interrogating the Mechanistic Features of Ni(I)-Mediated Aryl Iodide Oxidative Addition Using Electroanalytical and Statistical Modeling Techniques

While the oxidative addition of Ni(I) to aryl iodides has been commonly proposed in catalytic methods, an in-depth mechanistic understanding of this fundamental process is still lacking. Herein, we describe a detailed mechanistic study of the oxidative addition process using electroanalytical and statistical modeling techniques. Electroanalytical techniques allowed rapid measurement of the oxidative addition rates for a diverse set of aryl iodide substrates and four classes of catalytically relevant complexes (Ni(MeBPy), Ni(MePhen), Ni(Terpy), and Ni(BPP)). With >200 experimental rate measurements, we were able to identify essential electronic and steric factors impacting the rate of oxidative addition through multivariate linear regression models. This has led to a classification of oxidative addition mechanisms, either through a three-center concerted or halogen-atom abstraction pathway based on the ligand type. A global heat map of predicted oxidative addition rates was created and shown applicable to a better understanding of the reaction outcome in a case study of a Ni-catalyzed coupling reaction.

[Type III secretory protein SINC of Chlamydia psittaci promotes host cell autophagy by activating the MAPK/ERK signaling pathway]

OBJECTIVE

To investigate the effects of SINC, a secreted protein of Chlamydia psittaci, on autophagy of host cells and the role of MAPK/ERK signaling pathway in mediating SINC-induced autophagy.

METHODS

RAW 264.7 cells treated with recombinant SINC were examined for changes in expression levels of LC3-II, Beclin-1, phosphorylated and total ERK1/2 using Western blotting. The expression level of LC3 in the treated cells was detected using immunofluorescence analysis, and the formation of autophagosomes and autolysosomes was observed with transmission electron microscopy (TEM). The effect of pretreatment with U0126 (a specific ERK inhibitor) on the expression levels of LC3-II and Beclin-1 in RAW 264.7 cells exposed to different concentrations of SINC was examined using Western blotting, and LC3 puncta in the cells was detected with immunofluorescence analysis.

RESULTS

The expression levels of LC3-II and Beclin-1 were the highest in RAW 264.7 cells treated with 2 μg/mL SINC for 12h. Immunofluorescence analysis showed exposure to SINC significantly increased the number of cells containing LC3 puncta, where the presence of autophagosomes and autolysosomes was detected. Exposure to 2 μg/mL SINC for 15 min resulted in the most significant increase of the ratios of p-ERK1/2/ERK1/2 in RAW 264.7 cells. Pretreatment of the cells with U0126 prior to SINC exposure significantly decreased the ratio of p-ERK1/2/ERK1/2, lowered the expression levels of LC3-II and Beclin-1, and decreased LC3 aggregation in the cells.

CONCLUSIONS

SINC exposure can induce autophagy in RAW 264.7 cells by activating the MAPK/ERK signaling pathway.

Uniaxial cyclic stretch enhances osteogenic differentiation of OPLL-derived primary cells via YAP-Wnt/β-catenin axis

The pathogenesis of posterior longitudinal ligament ossification (OPLL) remains inadequately understood. Mechanical stimulation is one of the important pathogenic factors in OPLL. As one of the mechanical stimulation transduction signals, the yes-associated protein (YAP) interacts with the Wnt/β-catenin signalling pathway, which plays an important role in osteogenic differentiation. This study aimed to demonstrate the role of YAP-Wnt/β-catenin axis in cell differentiation induced by mechanical stress. Primary cells extracted from posterior longitudinal ligament tissues from OPLL or non-OPLL patients were subjected to sinusoidal uniaxial cyclic stretch (5 %, 0.5 Hz, 3 d). The expression of runt-related transcription factor 2, collagen I, osterix, osteocalcin and alkaline phosphatase were compared between the static and the experimental groups. In addition, the cytoskeleton was detected using phalloidin staining while YAP phosphorylation states and nuclear location were identified using immunofluorescence. The results showed that mechanical stretching loading increased the expression of osteogenic genes and proteins in the OPLL group, while it had no significant effect on the control group. When OPLL cells were stretched, YAP exhibited an obvious nuclear translocation and the Wnt/β-catenin pathway was activated. Knocking down YAP or β-catenin could weaken the impact upon osteogenic differentiation induced by mechanical stimulation. YAP-mediated mechanical stimulation promoted osteogenic differentiation of OPLL cells through Wnt/β-catenin pathway and this progress was independent of the Hippo pathway.

Three-Stage Conversion of Chemically Inert n-Heptane to α-Hydrazino Aldehyde Based on Bioelectrocatalytic C-H Bond Oxyfunctionalization

Simple petrochemical feedstocks are often the starting material for the synthesis of complex commodity and fine and specialty chemicals. Designing synthetic pathways for these complex and specific molecular structures with sufficient chemo-, regio-, enantio-, and diastereo-selectivity can expand the existing petrochemicals landscape. The two overarching challenges in designing such pathways are selective activation of chemically inert C-H bonds in hydrocarbons and systematic functionalization to synthesize complex structures. Multienzyme cascades are becoming a growing means of overcoming the first challenge. However, extending multienzyme cascade designs is restricted by the arsenal of enzymes currently at our disposal and the compatibility between specific enzymes. Here, we couple a bioelectrocatalytic multienzyme cascade to organocatalysis, which are two distinctly different classes of catalysis, in a single system to address both challenges. Based on the development and utilization of an anthraquinone (AQ)-based redox polymer, the bioelectrocatalytic step achieves regioselective terminal C-H bond oxyfunctionalization of chemically inert n-heptane. A second biocatalytic step selectively oxidizes the resulting 1-heptanol to heptanal. The succeeding inherently simple and durable l-proline-based organocatalysis step is a complementary partner to the multienzyme steps to further functionalize heptanal to the corresponding α-hydrazino aldehyde. The "three-stage" streamlined design exerts much control over the chemical conversion, which renders the collective system a versatile and adaptable model for a broader substrate scope and more complex C-H functionalization.

Investigating Oxidative Addition Mechanisms of Allylic Electrophiles with Low-Valent Ni/Co Catalysts Using Electroanalytical and Data Science Techniques

The catalysis by a π-allyl-Co/Ni complex has drawn significant attention recently due to its distinct reactivity in reductive Co/Ni-catalyzed allylation reactions. Despite significant success in reaction development, the critical oxidative addition mechanism to form the π-allyl-Co/Ni complex remains unclear. Herein, we present a study to investigate this process with four catalysis-relevant complexes: Co(^MeBPy)Br₂, Co(^MePhen)Br₂, Ni(^MeBPy)Br₂, and Ni(^MePhen)Br₂. Enabled by an electroanalytical platform, Co(I)/Ni(I) species were found responsible for the oxidative addition of allyl acetate. Kinetic features of different substrates were characterized through linear free-energy relationship (Hammett-type) studies, statistical modeling, and a DFT computational study. In this process, a coordination-ionization-type transition state was proposed, sharing a similar feature with Pd(0)-mediated oxidative addition in Tsuji-Trost reactions. Computational and ligand structural analysis studies support this mechanism, which should provide key information for next-generation catalyst development.

[Research advances on the application of carbon dots in wound treatment]

Chronic and infectious wound healing has always been an issue of concern in clinical and scientific research, in which bacterial infection and oxidative damage are the key factors hindering wound healing. Carbon dots, as a new material, has attracted much attention because of its unique physical and chemical properties and good biological safety. In recent years, the researches on the antibacterial property, antioxidant, and photoluminescence properties of carbon dots are more and more extensive and carbon dots have great potential in the treatment of chronic and infectious wounds. This paper reviews the research progress of carbon dots in three aspects: antibacterial, anti-oxidation and monitoring of wound infection are reviewed, and further discusses its specific mechanism, potential research direction, and application prospect.

Evidence of a Near-Threshold Resonance in ^{11}B Relevant to the β-Delayed Proton Emission of ^{11}Be

A narrow near-threshold proton-emitting resonance (E_{x}=11.4  MeV, J^{π}=1/2^{+}, and Γ_{p}=4.4  keV) was directly observed in ^{11}B via proton resonance scattering. This resonance was previously inferred in the β-delayed proton emission of the neutron halo nucleus ^{11}Be. The good agreement between both experimental results serves as a ground to confirm the existence of such exotic decay and the particular behavior of weakly bound nuclei coupled to the continuum. R-matrix analysis shows a sizable partial decay width for both, proton and α (Γ_{α}=11  keV) emission channels.

Cobalt-electrocatalytic HAT for functionalization of unsaturated C-C bonds

The study and application of transition metal hydrides (TMHs) has been an active area of chemical research since the early 1960s¹, for energy storage, through the reduction of protons to generate hydrogen^2,3, and for organic synthesis, for the functionalization of unsaturated C-C, C-O and C-N bonds^4,5. In the former instance, electrochemical means for driving such reactivity has been common place since the 1950s⁶ but the use of stoichiometric exogenous organic- and metal-based reductants to harness the power of TMHs in synthetic chemistry remains the norm. In particular, cobalt-based TMHs have found widespread use for the derivatization of olefins and alkynes in complex molecule construction, often by a net hydrogen atom transfer (HAT)⁷. Here we show how an electrocatalytic approach inspired by decades of energy storage research can be made use of in the context of modern organic synthesis. This strategy not only offers benefits in terms of sustainability and efficiency but also enables enhanced chemoselectivity and distinct, tunable reactivity. Ten different reaction manifolds across dozens of substrates are exemplified, along with detailed mechanistic insights into this scalable electrochemical entry into Co-H generation that takes place through a low-valent intermediate.

Association between isolated diastolic hypertension and cardiovascular events: a systematic review and meta-analysis of prospective cohorts

Background

Isolated diastolic hypertension (IDH) is a subtype of hypertension, which is defined as systolic blood pressure (SBP) <140 mmHg and diastolic blood pressure (DBP) ≥90 mmHg by 2018 European Society of Cardiology (ESC) guideline and 2019 National Institute for Health and Care Excellent (NICE). Whereas some previous studies have demonstrated the significant association between IDH and cardiovascular (CV) events, some have not.

Purpose

To assess the association between IDH and the risk of CV events, CV mortality, and all-cause mortality.

Methods

We conducted a systematic search for publications using Medline, Embase, and the Cochrane Library from inception through March 2021 for prospective cohort studies exploring the association between IDH and CV events, CV mortality, and all-cause mortality. Relative risks (RR) or hazard ratios were extracted from the selected studies. Random effect models with inverse variance weighting were used to calculate the pooled RR and 95% confidence interval (CI). The primary outcome was a composite of total CV events including CV mortality. The secondary outcomes were CV mortality and all-cause mortality. We defined the IDH as SBP <140 mmHg and DBP ≥90 mmHg, reference group as BP less than 140/90mmHg.

Results

Overall, 15 studies were identified including 1049587 participants (5.5% IDH). For the primary outcome, IDH was significantly associated with risk of CV events (RR, 1.40 [95% CI, 1.18–1.66], p<0.001). The increased risk of CV events was also observed in subgroup analyses based on age (less or more than 50) and sex. However, in further stratified analysis based on geographical region, only the Asia population showed a significant association with increased risk of CV events, whereas results were null in Europe and North America populations. For the secondary outcomes, IDH was significantly associated with increased CV mortality (RR [95% CI], 1.41 [1.12–1.78], p<0.001) but not with all-cause mortality (RR [95% CI], 1.13 [0.86–1.48], p=0.378). The sensitivity analysis showed the overall results did not vary significantly after exclusion of any one study.

Conclusions

IDH is associated with increased risk of CV events and CV mortality. Further, more large-scale prospective epidemiological cohorts are needed to confirm our conclusion.

Funding Acknowledgement

Type of funding sources: None. Primary outcomeSecondary outcomes

Effects of miR-195 on diabetic nephropathy rats through targeting TLR4 and blocking NF-κB pathway

OBJECTIVE

The aim of this study was to explore the effects of micro ribonucleic acid (miR)-195 on diabetic nephropathy (DN) rats through targeting Toll-like receptor 4 (TLR4) and inhibiting the nuclear factor-κB (NF-κB) signaling pathway.

MATERIALS AND METHODS

The model of DN was first successfully established in rats. All rats were randomly divided into six groups, including control group (n=20), model group (n=20), 25 nM miR-195 mimics group (25 nM M group, n=20), 50 nM M group (n=20), 25 nM miR-195 inhibitor group (25 nM I group, n=20), and 50 nM I group (n=20). Urine volume, proteins and inflammatory factors were detected in each group, respectively. Subsequently, macrophages were cultured and transfected in vitro. The mRNA expressions of miR-195 and TLR4 in control group and model groups were determined using fluorescence quantitative polymerase chain reaction (qPCR). The protein expressions of TLR4 and NF-κB in macrophages were determined using Western blotting. Furthermore, the proliferation of macrophages was detected via cell counting kit-8 (CCK-8) assay.

RESULTS

Compared with model group, 24-h urine volume, urine protein, creatinine, urea nitrogen, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and IL-6 levels declined significantly in 25 nM M group and 50 nM M group (p<0.05). However, they increased significantly in 25 nM I group and 50 nM I group (p<0.05). It could be suggested that miR-195 mimics might relieve the symptoms of DN rats. In kidney tissues in DN, miR-195 was lowly expressed, whereas TLR4 was highly expressed (p<0.01). This suggested that there was a negative correlation between the mRNA expressions of miR-195 and TLR4 (r2=0.4836, p=0.0007). After overexpression of miR-195, the protein expression of TLR4 was significantly reduced (p<0.01), indicating that miR-195 could negatively regulate the protein expression of TLR4. Besides, the protein expressions of TLR4 and NF-κB in si-TLR4 group were evidently lower than those in NC group (p<0.01). Meanwhile, they also had significant differences in si-TLR4 group compared with si-TLR4 + miR-195 inhibitor group (p<0.05). The above results demonstrated that the protein expressions of TLR4 and NF-κB in macrophages could be markedly inhibited by si-TLR4, but be promoted by si-TLR4 + miR-195 inhibitor. CCK-8 assay demonstrated that the proliferation ability of macrophages was remarkably weaker in miR-195 mimics group than NC group (p<0.001). Furthermore, it was also significantly weaker in si-TLR4 + miR-195 inhibitor group than si-TLR4 group (p<0.05).

CONCLUSIONS

MiR-195 reduces the release of inflammatory factors and inhibits the proliferation of macrophages through targeting TLR4 and blocking the NF-κB pathway, thereby alleviating the symptoms of DN rats.

N-Ammonium Ylide Mediators for Electrochemical C-H Oxidation

The site-specific oxidation of strong C(sp³)-H bonds is of uncontested utility in organic synthesis. From simplifying access to metabolites and late-stage diversification of lead compounds to truncating retrosynthetic plans, there is a growing need for new reagents and methods for achieving such a transformation in both academic and industrial circles. One main drawback of current chemical reagents is the lack of diversity with regard to structure and reactivity that prevents a combinatorial approach for rapid screening to be employed. In that regard, directed evolution still holds the greatest promise for achieving complex C-H oxidations in a variety of complex settings. Herein we present a rationally designed platform that provides a step toward this challenge using N-ammonium ylides as electrochemically driven oxidants for site-specific, chemoselective C(sp³)-H oxidation. By taking a first-principles approach guided by computation, these new mediators were identified and rapidly expanded into a library using ubiquitous building blocks and trivial synthesis techniques. The ylide-based approach to C-H oxidation exhibits tunable selectivity that is often exclusive to this class of oxidants and can be applied to real-world problems in the agricultural and pharmaceutical sectors.

Atom-Economical Cross-Coupling of Internal and Terminal Alkynes to Access 1,3-Enynes

Selective carbon-carbon (C-C) bond formation in chemical synthesis generally requires prefunctionalized building blocks. However, the requisite prefunctionalization steps undermine the overall efficiency of synthetic sequences that rely on such reactions, which is particularly problematic in large-scale applications, such as in the commercial production of pharmaceuticals. Herein, we describe a selective and catalytic method for synthesizing 1,3-enynes without prefunctionalized building blocks. In this transformation several classes of unactivated internal acceptor alkynes can be coupled with terminal donor alkynes to deliver 1,3-enynes in a highly regio- and stereoselective manner. The scope of compatible acceptor alkynes includes propargyl alcohols, (homo)propargyl amine derivatives, and (homo)propargyl carboxamides. This method is facilitated by a tailored P,N-ligand that enables regioselective addition and suppresses secondary E/Z-isomerization of the product. The reaction is scalable and can operate effectively with as low as 0.5 mol % catalyst loading. The products are versatile intermediates that can participate in various downstream transformations. We also present preliminary mechanistic experiments that are consistent with a redox-neutral Pd(II) catalytic cycle.

Nonequilibrium pattern formation in circularly confined two-dimensional systems with competing interactions

We numerically investigate the nonequilibrium behaviors of classic particles with competing interactions confined in a two-dimensional logarithmic trap. We reveal a quench-induced surprising dynamics exhibiting rich dynamic patterns depending upon confinement strength and trap size, which is attributed to the time-dependent competition between interparticle repulsions and attractions under a circular confinement. Moreover, in the collectively diffusive motions of the particles, we find that the emergence of dynamic structure transformation coincides with a diffusive mode transition from superdiffusion to subdiffusion. These findings are likely useful in understanding the pattern selection and evolution in various chemical and biological systems in addition to modulated systems, and add a new route to tailoring the morphology of pattern-forming systems.

Analyzing mechanisms in Co(i) redox catalysis using a pattern recognition platform

Redox catalysis has been broadly utilized in electrochemical synthesis due to its kinetic advantages over direct electrolysis. The appropriate choice of redox mediator can avoid electrode passivation and overpotential, which strongly inhibit the efficient activation of substrates in electrolysis. Despite the benefits brought by redox catalysis, establishing the precise nature of substrate activation remains challenging. Herein, we determine that a Co(i) complex bearing two N,N,N-tridentate ligands acts as a competent redox catalyst for the reduction of benzyl bromide substrates. Kinetic studies combining electroanalytical techniques with multivariable linear-regression analysis were conducted, disclosing an outer-sphere electron-transfer mechanism, which occurs in concert with C–Br bond cleavage. Furthermore, we apply a pattern recognition platform to distinguish between mechanisms in the activation of benzyl bromides, found to be dependent on the ligation state of the cobalt(i) center and ligand used.

Through kinetic studies combining electroanalytical techniques with multivariable linear-regression (MLR) analysis, a pattern recognition platform is established to determine the electron-transfer mechanism (inner-sphere or outer-sphere) of an electrochemical reduction of benzyl bromides, mediated by different cobalt complexes.

In Xenopus ependymal cilia drive embryonic CSF circulation and brain development independently of cardiac pulsatile forces

BACKGROUND

Hydrocephalus, the pathological expansion of the cerebrospinal fluid (CSF)-filled cerebral ventricles, is a common, deadly disease. In the adult, cardiac and respiratory forces are the main drivers of CSF flow within the brain ventricular system to remove waste and deliver nutrients. In contrast, the mechanics and functions of CSF circulation in the embryonic brain are poorly understood. This is primarily due to the lack of model systems and imaging technology to study these early time points. Here, we studied embryos of the vertebrate Xenopus with optical coherence tomography (OCT) imaging to investigate in vivo ventricular and neural development during the onset of CSF circulation.

METHODS

Optical coherence tomography (OCT), a cross-sectional imaging modality, was used to study developing Xenopus tadpole brains and to dynamically detect in vivo ventricular morphology and CSF circulation in real-time, at micrometer resolution. The effects of immobilizing cilia and cardiac ablation were investigated.

RESULTS

In Xenopus, using OCT imaging, we demonstrated that ventriculogenesis can be tracked throughout development until the beginning of metamorphosis. We found that during Xenopus embryogenesis, initially, CSF fills the primitive ventricular space and remains static, followed by the initiation of the cilia driven CSF circulation where ependymal cilia create a polarized CSF flow. No pulsatile flow was detected throughout these tailbud and early tadpole stages. As development progressed, despite the emergence of the choroid plexus in Xenopus, cardiac forces did not contribute to the CSF circulation, and ciliary flow remained the driver of the intercompartmental bidirectional flow as well as the near-wall flow. We finally showed that cilia driven flow is crucial for proper rostral development and regulated the spatial neural cell organization.

CONCLUSIONS

Our data support a paradigm in which Xenopus embryonic ventriculogenesis and rostral brain development are critically dependent on ependymal cilia-driven CSF flow currents that are generated independently of cardiac pulsatile forces. Our work suggests that the Xenopus ventricular system forms a complex cilia-driven CSF flow network which regulates neural cell organization. This work will redirect efforts to understand the molecular regulators of embryonic CSF flow by focusing attention on motile cilia rather than other forces relevant only to the adult.

A Computer-Interpretable Guideline for COVID-19: Rapid Development and Dissemination

Background

COVID-19 is a global pandemic that is affecting more than 200 countries worldwide. Efficient diagnosis and treatment are crucial to combat the disease. Computer-interpretable guidelines (CIGs) can aid the broad global adoption of evidence-based diagnosis and treatment knowledge. However, currently, no internationally shareable CIG exists.

Objective

The aim of this study was to establish a rapid CIG development and dissemination approach and apply it to develop a shareable CIG for COVID-19.

Methods

A 6-step rapid CIG development and dissemination approach was designed and applied. Processes, roles, and deliverable artifacts were specified in this approach to eliminate ambiguities during development of the CIG. The Guideline Definition Language (GDL) was used to capture the clinical rules. A CIG for COVID-19 was developed by translating, interpreting, annotating, extracting, and formalizing the Chinese COVID-19 diagnosis and treatment guideline. A prototype application was implemented to validate the CIG.

Results

We used 27 archetypes for the COVID-19 guideline. We developed 18 GDL rules to cover the diagnosis and treatment suggestion algorithms in the narrative guideline. The CIG was further translated to object data model and Drools rules to facilitate its use by people who do not employ the non-openEHR archetype. The prototype application validated the correctness of the CIG with a public data set. Both the GDL rules and Drools rules have been disseminated on GitHub.

Conclusions

Our rapid CIG development and dissemination approach accelerated the pace of COVID-19 CIG development. A validated COVID-19 CIG is now available to the public.

Suppressions of vibration in the Tip-Tilt mirror control system by add-on controller

Tip-Tilt mirrors play an important role in astronomical telescopes requiring the tracking performance at the level of microradian or sub-microradian. However, the closed-loop performance suffers a lot from the low-sample rate and time delay of image sensors. Especially, this issue is under the condition of vibrations, because dynamic behaviors are complex and the models are difficult to be obtained accurately. Another challenging issue comes from the measurement of vibrations and its extraction for the closed-loop control. This paper proposes a new method based on an add-on controller of the Tip-Tilt mirror to mitigate telescope vibrations. The proposed method only uses Tip-Tilt errors from an image sensor to implement a disturbance observer, which is not being restricted by an accurate model. As a result, the closed-loop performance can be optimized by designing of a proper Q-filter. To suppress the low-frequency and high-frequency vibrations, a novel Q-filter combining a lowpass filter and a bandpass filter is proposed here. The improved control method is validated by both simulation and experiment in the tip-tilt mirror control system under the condition of vibrations.

Open-source raspberry Pi-based operant box for translational behavioral testing in rodents

BACKGROUND

Rodents have been used for decades to probe neural circuits involved in behavior. Increasingly, attempts have been developed to standardize training paradigms across labs; and to use visual/auditory paradigms that can be also tested in humans. Commercially available systems are expensive and thus do not scale easily, and are not optimized for electrophysiology.

NEW METHOD

Using the rich open-source technology built around Raspberry Pi, we were able to develop an inexpensive (<$1000) visual-screen based operant chamber with electrophysiological and optogenetic compatibility. The chamber is operated within MATLAB/Simulink, a commonly used scientific programming language allowing for rapid customization.

RESULTS

Here, we describe and provide all relevant details needed to develop and produce these chambers, and show examples of behavior and electrophysiology data collected using these chambers. We also include all of the tools needed to allow readers to build and develop their own boxes (CAD models for 3D printing and laser-cutting; PCB-board design; all bill of materials for required parts and supplies, and some examples of Simulink models to operate the boxes).

COMPARISON WITH EXISTING METHODS

The new boxes are far more cost-effective than commercially available environments and allow for the combination of automated behavioral testing with electrophysiological read-outs with high temporal precision.

CONCLUSION

These open-source boxes can be used for labs interested in developing high-throughput visual/auditory behavioral assays for ∼ 10th the cost of commercial systems.

Rate of colorectal neoplasia in patients with Hodgkin lymphoma

AIM

Survivors of Hodgkin lymphoma (HL) are at increased risk of breast, lung, thyroid, stomach, pancreatic and colon cancer. There is limited information on the utility of endoscopic screening for colon cancer. We aimed to describe the adenoma detection rate (ADR) in patients with HL to determine the appropriate timing of colonoscopy screening.

METHOD

We retrospectively studied patients with HL who underwent colonoscopy between 2000 and 2017.

RESULTS

A total of 251 patients underwent colonoscopy. Eighty (32%) patients had 151 colonic polyps. Thirty per cent of the polyps exhibited high-grade dysplasia, and invasive colon adenocarcinoma was found in 10 patients. Patients with the nodular sclerosing subtype of HL had a significantly lower ADR than others (P = 0.002). The ADR was 5% in patients younger than 35 years (n = 64), 23% in patients between 35 and 40 years of age (n = 22), 39% in patients between 40 and 50 years of age (n = 51) and 46% in patients older than 50 years (n = 114).

[Comparison the clinical efficacy of 3D versus 2D total laparoscopic thyroidectomy for thyroid cancer by via-breast approach]

Objective:To summarize and analyze the clinical efficacy of 3D and 2D laparoscopic surgery in thyroidectomy for thyroid cancer. Method: Thirty-seven patients with early-differentiated thyroid cancer underwent laparoscopic surgery from August 2016 to November 2018. Their clinical data were retrospectively analyzed. They were divided into 3D laparoscopic group and 2D laparoscopic group based on laparoscopic imaging systems. The perioperative clinical indicators and postoperative complications of the two groups were compared. Result: Compared with the 2D laparoscopic group, the 3D laparoscopic group had shorter operation time and less bleeding, and the incidence of postoperative complications was less, but the differences between the two groups were not statistically significant(P>0.05). Conclusion: Compared with the 2D laparoscopic thyroidectomy, 3D laparoscopic thyroidectomy for thyroid cancer allows higher surgical precision, shorter operation time, lower operation risk and smoother surgical procedure, thus improves surgical efficiency.

Quantum Quench and Nonequilibrium Dynamics in Lattice-Confined Spinor Condensates

We present an experimental study on nonequilibrium dynamics of a spinor condensate after it is quenched across a superfluid to Mott insulator (MI) phase transition in cubic lattices. Intricate dynamics consisting of spin-mixing oscillations at multiple frequencies are observed in time evolutions of the spinor condensate localized in deep lattices after the quantum quench. Similar spin dynamics also appear after spinor gases in the MI phase are suddenly moved away from their ground states via quenching magnetic fields. We confirm these observed spectra of spin-mixing dynamics can be utilized to reveal atom number distributions of an inhomogeneous system, and to study transitions from two-body to many-body dynamics. Our data also imply the nonequilibrium dynamics depend weakly on the quench speed but strongly on the lattice potential. This enables precise measurements of the spin-dependent interaction, a key parameter determining the spinor physics.

Response of maize photosynthesis to high temperature: Implications for modeling the impact of global warming

Negative impacts of increased temperature on maize yield are anticipated using simulation models. However, some temperature functions are parameterized with partial information. There is limited information on photosynthesis response to high temperature in modern maize hybrids. Improved photosynthesis-temperature functions are key for realistic yield simulations. Our experiment was aimed at building a functional relationship between photosynthesis and air temperature exploring temperature ranges relevant for global warming simulations. Maize hybrids from cold, temperate, and subtropical regions were included in the study to assess genetic adaptation. Results showed a trilinear response to temperature with an optimum of 40 °C. No genetic adaptation was observed among the diverse set of hybrids evaluated. Results contrast with common temperature-limiting functions indicating a decline in carbon assimilation above 30-33 °C. Our results suggest possible overestimations of negative impacts of global warming on maize yield due to the use of inadequate response functions relating carbon assimilation to temperature.

[Surgical treatment of uremic secondary hyperparathyroidism complicated with thyroid nodules]

Objective:To investigate the surgical treatment of secondary hyperparathyroidism(SHPT) with thyroid nodule(TN) in uremic patients.Method:The clinical data of 26 patients diagnosed as SHPT combined with TN were retrospectively analyzed.Result:The patients underwent total parathyroidectomy and parathyroid granuless were transplanted subcutaneously into the forearm. The levels of parathyroid hormone,alkaline phosphatase,serum calcium,serum phosphorus and calcium-phosphorus product in 6 months and 12 months after operation were significantly lower than those before operation(P<0.01).The quality of life assessed by KDQOL-SF scale was significantly higher than that before operation(P<0.01). Concomtiant TN was operated simultaneously, and gravel calcification was significantly associated with papillary thyroid carcinoma(P<0.01).Conclusion:Total parathyroidectomy plus subcutaneous minimal forearm autograft and concurrent surgery with TN are feasible, and can not only properly treat TN, but also significantly improve SHPT-related prognosis and quality of life. We should be alert to the possibility of malignant TN in SHPT background, especially those with grit calcification.

[Post-marketing multi-center safety surveillance of inactivated enterovirus A71 vaccine (Vero cell)]

Objective: To evaluate the post-marketing safety profiles of the inactivated enterovirus type 71 (EV-A71) vaccine (Vero cell) after routine inoculation. Methods: Eleven cities of Zhejiang Province, Fengtai district of Beijing, Qinnan district, two counties as Pingle and Pingguo of Guangxi Zhuang Autonomous Region, and Dongtai city of Jiangsu Province were selected as the field sites. A total of 45 239 subjects were enrolled in this study from children who seeked the vaccination of EV-A71 vaccine during the period from July, 2016 to June, 2018. Different sampling method were adopted in different sites. All vaccinated children were invited to participate in the study in Fengtai and Dongtai, however, systematic sampling method were adopted in other sites. Active surveillance was conducted and information about adverse reactions (ARs) occurred in 30 min, 3 d and 30 d following each dose of EV-A71 immunization was collected by field observation, phone-call or face-to-face interview. The incidence of ARs in different types, symptoms and grades were described. Results: In total, there were 45 239 children who received 71 243 doses EV-A71 vaccine. The overall incidence of ARs was 1.079% (769 doses), with the highest incidence of 1.182% (177/14 973) in 5-11 month group and the lowest incidence of 0.849% (18/2 119) in ≥ 36 month group among different age groups. There was a higher incidence in solicited ARs, which was 1.047% (746 doses). The incidences of grade 1 and grade 2 ARs were also higher, which were 0.404% (288 doses) and 0.554% (395 doses), respectively. No grade 4 ARs occurred. The doses of the first and the second vaccination was 40 736 and 30 507, respectively, and the incidences of ARs were 1.281% (522 doses) and 0.810% (247 doses). Also, the incidences of ARs were 0.091% (37 doses) and 0.043% (13 doses) in local, and 1.168% (476 doses) and 0.760% (232 doses) in system. The symptoms of ARs after the two doses of vaccination were basically the same. Redness at the injection site was the most common local ARs after each dose vaccination, with doses of 24 and 11, while fever was the most common systemic ARs, with doses of 362 and 190. Moreover, ARs mainly occurred in 30 min to 3 d after each dose vaccination, with incidence of 1.016% (414 doses) and 0.698% (213 doses) in the first and second dose, respectively. Conclusion: The ARs had a low incidence after vaccination in children and most were mild or moderate. EV-A71 vaccine with good safety is suitable for inoculation in a large scale.

[Comparison of commercial HIV-1 viral load tests by using proficiency test results in China, 2013- 2015]

Objective: To compare the bio-equivalence among commercial HIV-1 viral load tests, including EasyQ HIV-1 v2.0 (EasyQ) from bioMerieux NucliSens of France; VERSANT HIV-1 RNA 3.0 assay (bDNA) from Siemens Healthcare Diagnostics of USA; COBAS AmpliPrep/COBAS TaqMan HIV-1 test (Taqman) from Roche Molecular Diagnosis of USA; Abbott Real Time HIV-1 Kit (M2000) from Abbott Molecular of USA and two domestic HIV-1 viral load test kits (domestic kit) from DaAn Gene Company of Sun Yat-Sen University and Liaoning Bio-Pharmaceutical company of Northeast pharmaceutical group, by using proficiency test results in China from 2013 to 2015. Methods: A total of 2 954 proficiency test results, obtained from 22 positive samples of 6 proficiency tests in 155 laboratories conducted by China CDC were analyzed during 2013-2015. The results from each sample were first logarithmic transformed and then grouped according to the method used, the mean value of logarithmic results was calculated. Subsequently, 22 clusters of mean values were analyzed by Bland-Altman analysis for the consistency, and linear regression analysis for the interdependency. Results: The results indicated that, by taking Taqman as the reference, EasyQ, M2000, bDNA and domestic kit had good consistency (90%-100%) and interdependency. Conclusion: All the viral load tests were bio-equivalent. Moreover, according to the conversion formula derived from domestic proficiency test results, all the viral load results could be converted, which is critical for epidemiological analysis.

Abstract P6-13-03: Not presented

This abstract was not presented at the conference.

Citation Format: Glaspy J, Tang T, Rutty D, Yan X, Bondarenko I, Burdaeva O. Not presented [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-13-03.

Beyond first-line non-anthracycline-based chemotherapy for extranodal NK/T-cell lymphoma: clinical outcome and current perspectives on salvage therapy for patients after first relapse and progression of disease

Background

Current standard treatment, including non-anthracycline-based chemotherapy and optimal combining of radiotherapy, has dramatically improved outcomes of patients with extranodal natural killer/T-cell lymphoma (ENKTL) during the last decade. This study was conducted to investigate the clinical outcome of ENKTL patients with relapsed or progressive disease after initial current standard therapy.

Patients and methods

We retrospectively reviewed patients diagnosed with ENKTL at six centers in four countries (China, France, Singapore, and South Korea) from 1997 to 2015 and analyzed 179 patients who had relapsed or progressed after initial current standard therapy.

Results

After a median follow-up of 58.6 months (range 27.9-89.2), the median second progression-free survival (PFS) was 4.1 months [95% confidence interval (CI) 3.04-5.16] and overall survival (OS) was 6.4 months (95% CI 4.36-8.51). Multivariate Cox-regression analysis revealed that elevated lactate dehydrogenase, multiple extranodal sites (≥2), and presence of B symptoms were associated with inferior OS (P < 0.05). OS and PFS were significantly different according to both prognostic index of natural killer lymphoma (PINK) and PINK-E (Epstein-Barr virus) models. Salvage chemotherapy with l-asparaginase (l-Asp)-based regimens showed a significantly better clinical benefit to response rate and PFS, although it did not lead to OS improvement. First use of l-Asp in the salvage setting and l-Asp rechallenge at least 6 months after initial treatment were the best candidates for salvage l-Asp containing chemotherapy.

Conclusions

Most patients with relapsed or refractory ENKTL had poor prognosis with short survival. Further studies are warranted to determine the optimal treatment of patients with relapsed or refractory ENKTL.

Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma

Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.