An integrated single- and two-photon non-diffracting light-sheet microscope

We describe a fluorescence optical microscope with both single-photon and two-photon non-diffracting light-sheet excitations for large volume imaging. With a special design to accommodate two different wavelength ranges (visible: 400-700 nm and near infrared: 800-1200 nm), we combine the line-Bessel sheet (LBS, for single-photon excitation) and the scanning Bessel beam (SBB, for two-photon excitation) light sheet together in a single microscope setup. For a transparent thin sample where the scattering can be ignored, the LBS single-photon excitation is the optimal imaging solution. When the light scattering becomes significant for a deep-cell or deep-tissue imaging, we use SBB light-sheet two-photon excitation with a longer wavelength. We achieved nearly identical lateral/axial resolution of about 350/270 nm for both imagings. This integrated light-sheet microscope may have a wide application for live-cell and live-tissue three-dimensional high-speed imaging.

Mirrorless Optical Parametric Oscillation with Tunable Threshold in Cold Atoms

We report the demonstration of a mirrorless optical parametric oscillator with a tunable threshold in laser-cooled atoms with four-wave mixing (FWM) using electromagnetically induced transparency. Driven by two classical laser beams, the generated Stokes and anti-Stokes fields counterpropagate and build up efficient intrinsic feedback through the nonlinear FWM process. This feedback does not involve any cavity or spatially distributed microstructures. We observe the transition of photon correlation properties from the biphoton quantum regime (below the threshold) to the oscillation regime (above the threshold). The pump threshold can be tuned by varying the operating parameters. We achieve the oscillation with a threshold as low as 15  μW.

Quantum Heat Engine Using Electromagnetically Induced Transparency

We report an experiment demonstrating the generation of directional thermal radiation with a spectral brightness that is about 9 times greater than that of the ambient pumping reservoir. The experiment is based on the recent proposal for a nontraditional quantum heat engine and uses cold Rb atoms, electromagnetically induced transparency, and photon correlation spectroscopy [Phys. Rev. A 94, 053859 (2016)PLRAAN2469-992610.1103/PhysRevA.94.053859].

GAS2L1 Is a Centriole-Associated Protein Required for Centrosome Dynamics and Disjunction

Mitotic spindle formation and chromosome segregation require timely separation of the two duplicated centrosomes, and this process is initiated in late G2 by centrosome disjunction. Here we report that GAS2L1, a microtubule- and actin-binding protein, associates with the proximal end of mature centrioles and participates in centriole dynamics and centrosome disjunction. GAS2L1 attaches microtubules and actin to centrosomes, and the loss of GAS2L1 inhibits centrosome disjunction in G2 and centrosome splitting induced by depletion of the centrosome linker rootletin. Conversely, GAS2L1 overexpression induces premature centrosome separation, and this activity requires GAS2L1 association with actin, microtubules, and the microtubule end-binding proteins. The centrosome-splitting effect of GAS2L1 is counterbalanced by rootletin, reflecting the opposing actions of GAS2L1 and the centrosome linker. Our work reveals a GAS2L1-mediated centriole-tethering mechanism of microtubules and actin, which provide the forces required for centrosome dynamics and separation.

Stem cell-like transcriptional reprogramming mediates metastatic resistance to mTOR inhibition

Inhibitors of the mechanistic target of rapamycin (mTOR) are currently used to treat advanced metastatic breast cancer. However, whether an aggressive phenotype is sustained through adaptation or resistance to mTOR inhibition remains unknown. Here, complementary studies in human tumors, cancer models and cell lines reveal transcriptional reprogramming that supports metastasis in response to mTOR inhibition. This cancer feature is driven by EVI1 and SOX9. EVI1 functionally cooperates with and positively regulates SOX9, and promotes the transcriptional upregulation of key mTOR pathway components (REHB and RAPTOR) and of lung metastasis mediators (FSCN1 and SPARC). The expression of EVI1 and SOX9 is associated with stem cell-like and metastasis signatures, and their depletion impairs the metastatic potential of breast cancer cells. These results establish the mechanistic link between resistance to mTOR inhibition and cancer metastatic potential, thus enhancing our understanding of mTOR targeting failure.

A Distinct Pathway for Polar Exocytosis in Plant Cell Wall Formation

Post-Golgi protein sorting and trafficking to the plasma membrane (PM) is generally believed to occur via the trans-Golgi network (TGN). In this study using Nicotiana tabacum pectin methylesterase (NtPPME1) as a marker, we have identified a TGN-independent polar exocytosis pathway that mediates cell wall formation during cell expansion and cytokinesis. Confocal immunofluorescence and immunogold electron microscopy studies demonstrated that Golgi-derived secretory vesicles (GDSVs) labeled by NtPPME1-GFP are distinct from those organelles belonging to the conventional post-Golgi exocytosis pathway. In addition, pharmaceutical treatments, superresolution imaging, and dynamic studies suggest that NtPPME1 follows a polar exocytic process from Golgi-GDSV-PM/cell plate (CP), which is distinct from the conventional Golgi-TGN-PM/CP secretion pathway. Further studies show that ROP1 regulates this specific polar exocytic pathway. Taken together, we have demonstrated an alternative TGN-independent Golgi-to-PM polar exocytic route, which mediates secretion of NtPPME1 for cell wall formation during cell expansion and cytokinesis and is ROP1-dependent.

Subnatural-linewidth biphotons from a Doppler-broadened hot atomic vapour cell

Entangled photon pairs, termed as biphotons, have been the benchmark tool for experimental quantum optics. The quantum-network protocols based on photon-atom interfaces have stimulated a great demand for single photons with bandwidth comparable to or narrower than the atomic natural linewidth. In the past decade, laser-cooled atoms have often been used for producing such biphotons, but the apparatus is too large and complicated for engineering. Here we report the generation of subnatural-linewidth (<6 MHz) biphotons from a Doppler-broadened (530 MHz) hot atomic vapour cell. We use on-resonance spontaneous four-wave mixing in a hot paraffin-coated ⁸⁷Rb vapour cell at 63 °C to produce biphotons with controllable bandwidth (1.9-3.2 MHz) and coherence time (47-94 ns). Our backward phase-matching scheme with spatially separated optical pumping is the key to suppress uncorrelated photons from resonance fluorescence. The result may lead towards miniature narrowband biphoton sources.

ATM protein is located on presynaptic vesicles and its deficit leads to failures in synaptic plasticity

Ataxia telangiectasia is a multisystemic disorder that includes a devastating neurodegeneration phenotype. The ATM (ataxia-telangiectasia mutated) protein is well-known for its role in the DNA damage response, yet ATM is also found in association with cytoplasmic vesicular structures: endosomes and lysosomes, as well as neuronal synaptic vesicles. In keeping with this latter association, electrical stimulation of the Schaffer collateral pathway in hippocampal slices from ATM-deficient mice does not elicit normal long-term potentiation (LTP). The current study was undertaken to assess the nature of this deficit. Theta burst-induced LTP was reduced in Atm(-/-) animals, with the reduction most pronounced at burst stimuli that included 6 or greater trains. To assess whether the deficit was associated with a pre- or postsynaptic failure, we analyzed paired-pulse facilitation and found that it too was significantly reduced in Atm(-/-) mice. This indicates a deficit in presynaptic function. As further evidence that these synaptic effects of ATM deficiency were presynaptic, we used stochastic optical reconstruction microscopy. Three-dimensional reconstruction revealed that ATM is significantly more closely associated with Piccolo (a presynaptic marker) than with Homer1 (a postsynaptic marker). These results underline how, in addition to its nuclear functions, ATM plays an important functional role in the neuronal synapse where it participates in the regulation of presynaptic vesicle physiology.

A Mitochondrion-Specific Photoactivatable Fluorescence Turn-On AIE-Based Bioprobe for Localization Super-Resolution Microscope

A novel mitochondrion-specific photo-activatable fluorescence turn-on bioprobe, named as o-TPE-ON+, is designed and readily prepared, operating through a new photoactivatable mechanism of photocyclodehydrogenation. This bioprobe exhibits unique photoactivation behavior in cells, and is applied to super-resolution imaging of mitochondrion and its dynamic investigation in both fixed and live cells under physiological conditions without any external additives.

Multicolor 4D Fluorescence Microscopy using Ultrathin Bessel Light Sheets

We demonstrate a simple and efficient method for producing ultrathin Bessel (‘non-diffracting’) light sheets of any color using a line-shaped beam and an annulus filter. With this robust and cost-effective technology, we obtained two-color, 3D images of biological samples with lateral/axial resolution of 250 nm/400 nm, and high-speed, 4D volume imaging of 20 μm sized live sample at 1 Hz temporal resolution.

Shaping the Biphoton Temporal Waveform with Spatial Light Modulation

We demonstrate a technique for shaping the temporal wave function of biphotons generated from spatially modulated spontaneous four-wave mixing in cold atoms. We show that the spatial profile of the pump field can be mapped onto the biphoton temporal wave function in the group delay regime. The spatial profile of the pump laser beam is shaped by using a spatial light modulator. This spatial-to-temporal mapping enables the generation of narrow-band biphotons with controllable temporal waveforms.

The relationship between radiographic parameters and clinical outcome of distal radius fractures in elderly patients

PURPOSE OF THE STUDY

Treatment of distal radius fractures in elderly patients is controversial. This study explored the relationship between radiographic parameters and clinical outcomes of patients with distal radius fractures following conservative treatment. The study was done using radiographic measurements of distal radius fractures in elderly patients.

PATIENTS AND METHODS

Ninety-two active, healthy patients with conservatively managed distal radius fractures were included in the study. Functional and radiographic assessments were made 1 year after injury. Fifty patients who underwent corrective osteotomy comprised the control group. Radiographic parameters and clinical outcomes were compared between the two groups. The correlation coefficients of the radiographic parameters were analysed using multiple regression.

RESULT

Radius height (RH), volar tilt (VT) and Mayo wrist and Disabilities of the Arm, Shoulder and Hand (DASH) scores in the experimental group were significantly superior to those of the control group. There was no significant group difference in radial inclination. Multiple regression analysis revealed that the most important factor affecting functional outcome was RH, followed by VT.

DISCUSSION

RH and VT were significantly correlated with the clinical outcomes of conservative treatment of distal radius fractures. RH should be given foremost consideration in elderly patients. Preoperatively, surgeons should evaluate this parameter carefully and be prepared to treat injuries accordingly.

LEVEL OF EVIDENCE

Level IV retrospective study.

The Impact of Clinical Pharmacist Support on Patients Receiving Multi-drug Therapy for Coronary Heart Disease in China

The study determined pharmacist support on patients receiving multi-drug therapy for coronary heart disease by evaluating patient self-care ability, quality of life, and drug therapy compliance. In this study, ninety patients were randomly assigned to an experimental group (n=45) and a control group (n=45). The control group received conventional clinical care. The experimental group received clinical care plus pharmacist support that included medication review, patient education, lifestyle management, discharge guidance, and telephone follow-up. Eighty-five patients completed the study. Self-care ability and quality of life were evaluated before hospital discharge. The experimental group understood their condition better than the control group (P<0.05), the differences between the groups in understanding treatment goals, drug regimens, lifestyle modifications, psychogenic disorders, and satisfaction evaluations were more pronounced (P<0.01). At six-month follow-up, the difference between the groups in drug therapy compliance was P<0.01, as was success rate by intention-to-treat (77.8% vs. 48.9%) and per-protocol (81.4% vs. 52.4%). Two adverse drug reactions occurred in the experimental group and three in the control group. Pharmacist support improved self-care ability, quality of life, drug therapy compliance, and treatment success rate in coronary heart disease patients.

Diabetes nutrition therapy and dietary intake among individuals with Type 1 diabetes in China

AIMS

To describe the contribution of diabetes nutrition therapy to disease self-management among individuals with Type 1 diabetes in China and to estimate the association of diabetes nutrition therapy with dietary intake.

METHODS

The 3C Study was an epidemiological study of the coverage, cost and care of Type 1 diabetes in China. The data reported in the present study are from the 3C Nutrition Ancillary Study, a follow-up study conducted a mean ± sd of 1.6 ± 0.2 years later. Diabetes nutrition therapy was assessed by an interviewer-administered questionnaire. Dietary intake was assessed using three 24-h recalls. The association of diabetes nutrition therapy with dietary intake was estimated using ancova.

RESULTS

Participants (n = 100; 54% male) had a mean ± sd age of 41.7 ± 16.3 years and a mean ± sd diabetes duration of 11.8 ± 9.7 years. Fewer than half of the participants reported that they had 'ever' met with a dietitian. While 64% of participants were taught carbohydrate counting, only 12% 'ever' use this tool. Participants on insulin pumps and those testing ≥ 1 time/day reported greater dietary flexibility and higher fruit intakes compared with participants on other insulin regimens and testing less frequently. After adjustment for confounding by age and occupation, there were no consistent differences in dietary intake across subgroups of diabetes nutrition therapy.

CONCLUSIONS

In this sample of individuals with Type 1 diabetes in China there is little dietitian involvement or carbohydrate counting. Increased frequency of nutrition education in conjunction with intensified self-monitoring of blood glucose is needed to improve care.

A user-friendly two-color super-resolution localization microscope

We report a robust two-color method for super-resolution localization microscopy. Two-dye combination of Alexa647 and Alexa750 in an imaging buffer containing COT and using TCEP as switching regent provides matched and balanced switching characteristics for both dyes, allowing simultaneous capture of both on a single camera. Active sample locking stabilizes sample with 1nm accuracy during imaging. With over 4,000 photons emitted from both dyes, two-color superresolution images with high-quality were obtained in a wide range of samples including cell cultures, tissue sections and yeast cells.