The transport of liquids in softwood: timber as a model porous medium

Timber is the only widely used construction material we can grow. The wood from which it comes has evolved to provide structural support for the tree and to act as a conduit for fluid flow. These flow paths are crucial for engineers to exploit the full potential of timber, by allowing impregnation with liquids that modify the properties or resilience of this natural material. Accurately predicting the transport of these liquids enables more efficient industrial timber treatment processes to be developed, thereby extending the scope to use this sustainable construction material; moreover, it is of fundamental scientific value - as a fluid flow within a natural porous medium. Both structural and transport properties of wood depend on its micro-structure but, while a substantial body of research relates the structural performance of wood to its detailed architecture, no such knowledge exists for the transport properties. We present a model, based on increasingly refined geometric parameters, that accurately predicts the time-dependent ingress of liquids within softwood timber, thereby addressing this long-standing scientific challenge. Moreover, we show that for the minimalistic parameterisation the model predicts ingress with a square-root-of-time behaviour. However, experimental data show a potentially significant departure from this [Formula: see text] behaviour - a departure which is successfully predicted by our more advanced parametrisation. Our parameterisation of the timber microstructure was informed by computed tomographic measurements; model predictions were validated by comparison with experimental data. We show that accurate predictions require statistical representation of the variability in the timber pore space. The collapse of our dimensionless experimental data demonstrates clear potential for our results to be up-scaled to industrial treatment processes.

[Survival time and influencing factors in multidrug-resistant tuberculosis patients in Wuhan, 2006-2014]

Objective: To investigate the survival time of multidrug-resistant tuberculosis (MDR-TB) patients and the influential factors in Wuhan. Methods: The relevant information were collected from TB management information system, cause of death reporting system and medical records by trained doctors. The univariate and multivariate Cox proportional hazards model were applied to analyze the factors affecting survival time of patients. Results: A total of 552 patients with MDR-TB were included in the analysis. After the diagnosis of MDR-TB, the cumulative survival rates from the first year to the third year were 0.94, 0.88, and 0.80, respectively. The mortality density of MDR-TB patients was 6.52/100 person-years, and the median survival time was (89.52±1.85) months. Kaplan-Meier analysis showed that the cumulative survival rate of the standardized treatment group was significantly higher than that of the non-standardized treatment group (Log rank=101.070, P<0.001). Compared with the patients aged <30 years, the HR of the patients aged 30-years and ≥60 years were 2.987 (95%CI: 1.268-7.036), 4.957 (95%CI: 1.942-12.653). Compared with the patients with the education level of high school and above, the HR of the patients with education level of junior high school/primary school and below were 1.908 (95%CI: 1.152-3.160), 1.681(95%CI: 1.033-2.735). Compared with the patients without diabetes, the HR of the patients with diabetes was 1.961(95%CI: 1.347-2.854). Compared with the patients without other serious diseases, the HR of the patients with other serious diseases was 2.597 (95%CI: 1.820-3.706). Compared with the patients who had been treated less than one time, the HR of the patients having previous treatment with more than 2 times was 1.611 (95%CI: 1.077-2.409). Compared with patients receiving standard MDR regimen treatment, the HR of the patients receiving no standard MDR regimen treatment was 3.155 (95%CI: 2.132-4.670). Conclusions: The cumulative survival rate of MDR-TB patients without standard treatment was significantly lower than that of patients with standard treatment. Older age, low educational level, diabetes mellitus, other serious diseases, more than two times treatment in the past, and receiving no multi-drug resistance regimen treatment were the risk factors affecting the survival of MDR-TB patients.

[JNK/c-Jun signaling pathway mediates arginine vasopressin neuron regeneration by promoting cytoskeleton reconstruction in rats with electrical lesions of the pituitary stalk]

OBJECTIVE

To investigate the mechanism by which doublecortin promotes the recovery of cytoskeleton in arginine vasopressin (AVP) neurons in rats with electrical lesions of the pituitary stalk (PEL).

METHODS

Thirty-two SD rats were randomized into PEL group with electrical lesions of the pituitary stalk through the floor of the skull base (n=25) and sham operation group (n=7), and the daily water consumption (DWC), daily urine volume (DUV) and urine specific gravity (USG) of the rats were recorded. Four rats on day 1 and 7 rats on each of days 3, 7 and 14 after PEL as well as the sham-operated rats were sacrificed for detection of the expressions of β-Tubulin (Tuj1), doublecortin and caspase- 3 in the AVP neurons of the supraoptic nucleus using immunofluorescence assay and Western blotting.

RESULTS

After PEL, the rats exhibited a typical triphasic pattern of diabetes insipidus, with the postoperative days 1-2 as the phase one, days 3-5 as the phase two, and days 6-14 as the phase three. Immunofluorescent results indicated the repair of the AVP neurons evidenced by significantly increased doublecortin expressions in the AVP neurons following PEL; similarly, the expression of Tuj1 also increased progressively after PEL, reaching the peak level on day 7 after PEL. The apoptotic rates of the AVP neurons exhibited a reverse pattern of variation, peaking on postoperative day 3 followed by progressive reduction till day 14. Western blotting showed that the expressions of c-Jun and p-c-Jun were up-regulated significantly on day 3 (P &lt; 0.05) and 7 (P &lt; 0.01) after PEL, while an upregulated p-JNK expression was detected only on day 3 (P &lt; 0.05), as was consistent with the time-courses of neuronal recovery and apoptosis after PEL.

CONCLUSIONS

JNK/c-Jun pathway is activated after PEL to induce apoptosis of AVP neurons in the acute phase and to promote the repair of neuronal cytoskeleton by up-regulation of doublecortin and Tuj1 expressions.

Fine-tuning the photosynthetic light harvesting apparatus for improved photosynthetic efficiency and biomass yield

Photosynthetic electron transport rates in higher plants and green algae are light-saturated at approximately one quarter of full sunlight intensity. This is due to the large optical cross section of plant light harvesting antenna complexes which capture photons at a rate nearly 10-fold faster than the rate-limiting step in electron transport. As a result, 75% of the light captured at full sunlight intensities is reradiated as heat or fluorescence. Previously, it has been demonstrated that reductions in the optical cross-section of the light-harvesting antenna can lead to substantial improvements in algal photosynthetic rates and biomass yield. By surveying a range of light harvesting antenna sizes achieved by reduction in chlorophyll b levels, we have determined that there is an optimal light-harvesting antenna size that results in the greatest whole plant photosynthetic performance. We also uncover a sharp transition point where further reductions or increases in antenna size reduce photosynthetic efficiency, tolerance to light stress, and impact thylakoid membrane architecture. Plants with optimized antenna sizes are shown to perform well not only in controlled greenhouse conditions, but also in the field achieving a 40% increase in biomass yield.

Decrease of FGF19 contributes to the increase of fasting glucose in human in an insulin-independent manner

PURPOSE

The ileum-derived fibroblast growth factor 19 (FGF19) plays key roles in hepatic glucose homeostasis in animals in an insulin-independent manner. Here, we analyzed the association of FGF19 with glucose effectiveness (GE, the insulin-independent glucose regulation), as well as hepatic glucose production (HGP) in Chinese subjects.

METHODS

GE was measured by frequently sampled intravenous glucose tolerance test (FSIVGTT) in normal glucose tolerance (NGT), isolated-impaired glucose tolerance (I-IGT), and isolated-impaired fasting glucose (I-IFG) subjects. The oral glucose tolerance test-derived surrogate of GE (oGE) was determined in NGT, I-IFG, combined glucose intolerance (CGI), and type 2 diabetes (T2DM) subjects. HGP was assessed by labeled ([3-³H]-glucose) hyperinsulinemic-euglycemic clamp in NGT subjects. Insulin secretion and sensitivity were calculated by the hyperglycemic and hyperinsulinemic-euglycemic clamps in a subgroup of NGT, I-IGT, and I-IFG subjects. Serum FGF19 levels were determined by ELISA.

RESULTS

FGF19 positively correlated with GE (r = 0.29, P = 0.004) as determined by FSIVGTT. The result was further confirmed by oGE (r = 0.261, P < 0.001). FGF19 was negatively associated with FPG (r = - 0.228, P = 0.025), but the association no longer existed after adjusting for GE (r = - 0.177, P = 0.086). FGF19 was negatively associated with basal HGP (r = - 0.697, P = 0.006). However, the correlation between FGF19 and insulin secretion and sensitivity were not found.

CONCLUSIONS

FGF19 levels are associated positively with GE and negatively with HGP. The increase of FPG in human is at least partially due to the decrease of FGF19 in an insulin-independent manner.

Relationship between neuronal network architecture and naming performance in temporal lobe epilepsy: A connectome based approach using machine learning

Impaired confrontation naming is a common symptom of temporal lobe epilepsy (TLE). The neurobiological mechanisms underlying this impairment are poorly understood but may indicate a structural disorganization of broadly distributed neuronal networks that support naming ability. Importantly, naming is frequently impaired in other neurological disorders and by contrasting the neuronal structures supporting naming in TLE with other diseases, it will become possible to elucidate the common systems supporting naming. We aimed to evaluate the neuronal networks that support naming in TLE by using a machine learning algorithm intended to predict naming performance in subjects with medication refractory TLE using only the structural brain connectome reconstructed from diffusion tensor imaging. A connectome-based prediction framework was developed using network properties from anatomically defined brain regions across the entire brain, which were used in a multi-task machine learning algorithm followed by support vector regression. Nodal eigenvector centrality, a measure of regional network integration, predicted approximately 60% of the variance in naming. The nodes with the highest regression weight were bilaterally distributed among perilimbic sub-networks involving mainly the medial and lateral temporal lobe regions. In the context of emerging evidence regarding the role of large structural networks that support language processing, our results suggest intact naming relies on the integration of sub-networks, as opposed to being dependent on isolated brain areas. In the case of TLE, these sub-networks may be disproportionately indicative naming processes that are dependent semantic integration from memory and lexical retrieval, as opposed to multi-modal perception or motor speech production.

FDG-PET and MRI in the Evolution of New-Onset Refractory Status Epilepticus

BACKGROUND AND PURPOSE

New-onset refractory status epilepticus is a clinical condition characterized by acute and prolonged pharmacoresistant seizures without a pre-existing relevant neurologic disorder, prior epilepsy, or clear structural, toxic, or metabolic cause. New-onset refractory status epilepticus is often associated with antineuronal antibodies and may respond to early immunosuppressive therapy, reflecting an inflammatory element of the condition. FDG-PET is a useful diagnostic tool in inflammatory and noninflammatory encephalitis. We report here FDG-PET findings in new-onset refractory status epilepticus and their correlation to disease activity, other imaging findings, and outcomes.

MATERIALS AND METHODS

Twelve patients who met the criteria for new-onset refractory status epilepticus and who had FDG-PET and MR imaging scans and electroencephalography at a single academic medical center between 2008 and 2017 were retrospectively identified. Images were independently reviewed by 2 radiologists specialized in nuclear imaging. Clinical characteristics and outcome measures were collected through chart review.

RESULTS

Twelve patients underwent 21 FDG-PET scans and 50 MR imaging scans. Nine (75%) patients were positive for autoantibodies. All patients had identifiable abnormalities on the initial FDG-PET in the form of hypermetabolism (83%) and/or hypometabolism (42%). Eight (67%) had medial temporal involvement. All patients (n = 3) with N-methyl-D-aspartic acid receptor antibodies had profound bilateral occipital hypometabolism. Initial MR imaging findings were normal in 6 (50%) patients. Most patients had some degree of persistent hyper- (73%) or hypometabolism (45%) after immunosuppressive therapy. FDG-PET hypometabolism was predictive of poor outcome (mRS 4-6) at hospital discharge (P = .028).

CONCLUSIONS

Both FDG-PET hypometabolism and hypermetabolism are seen in the setting of new-onset refractory status epilepticus and may represent markers of disease activity.

Treatment Response Prediction of Nasopharyngeal Carcinoma Based on Histogram Analysis of Diffusional Kurtosis Imaging

BACKGROUND AND PURPOSE

The prediction of treatment response is important in planning and modifying the chemoradiation therapy regimen. This study aimed to explore the quantitative histogram indices for treatment-response prediction of nasopharyngeal carcinoma based on diffusional kurtosis imaging compared with a standard ADC value (ADC_standard).

MATERIALS AND METHODS

Thirty-six patients with an initial diagnosis of locoregionally advanced nasopharyngeal carcinoma and diffusional kurtosis imaging acquisitions before and after neoadjuvant chemotherapy were enrolled. Patients were divided into respond-versus-nonrespond groups after neoadjuvant chemotherapy and residual-versus-nonresidual groups after radiation therapy. Histogram parameters of diffusional kurtosis imaging-derived parameters (ADC, ADC coefficient corrected by the non-Gaussain model [D], apparent kurtosis coefficient without a unit [K]) were calculated. The ADC_standard was calculated on the basis of intravoxel incoherent movement data. The intraclass correlation coefficient, Kolmogorov-Smirnov test, Student t test or Mann-Whitney U test, and receiver operating characteristic analysis were performed.

RESULTS

Most of the parameters had good-to-excellent consistency (intraclass correlation coefficient = 0.675-0.998). The pre-ADC_standard, pre-ADC (10th, 25th, 50th percentiles), pre-D (10th, 25th, 50th percentiles), and pre-K_50th were significantly different between the respond and nonrespond groups, while the pre-ADC_10th, pre-K_90th, post-ADC_50th, post-K_75th, post-K_90th, and the percentage change of parameters before and after neoadjuvant chemotherapy (▵ADC_50th%) were significantly different between the residual and nonresidual groups (all P < .05). Receiver operating characteristic analysis indicated that setting pre-D_50th = 0.875 × 10^-3mm²/s as the cutoff value could result in optimal diagnostic performance for neoadjuvant chemotherapy response prediction (area under the curve = 0.814, sensitivity = 0.70, specificity = 0.92), while the post-K_90th = 1.035 (area under the curve = 0.829, sensitivity = 0.78, specificity = 0.72), and▵ADC_50th% = 0.253 (area under the curve = 0.833, sensitivity = 0.94, specificity = 0.72) were optimal for radiation therapy response prediction.

CONCLUSIONS

Histogram analysis of diffusional kurtosis imaging may potentially predict the neoadjuvant chemotherapy and short-term radiation therapy response in locoregionally advanced nasopharyngeal carcinoma, therefore providing evidence for modification of the treatment regimen.