Magnetic properties and critical behaviors of the nodal-line semimetal candidate ErIn3

The AuCu3-type intermetallic compoundsReIn3(Re= a rare earth ion) with type-IV magnetic space groups are predicted to show topologically nontrivial electronic states. Here, we grow ErIn3single crystals, and study their magnetic properties and critical behaviors by means of the magnetic susceptibility, and magnetization isotherm measurements. Combining a detailed analysis of the magnetic susceptibility and isothermal magnetization, we find that this compound harbors a complicated magnetic phase diagram, and its magnetic moment arrangement appears not to simply follow the fashion as observed in the isostructural counterpart GdIn3(it adopts a conventional type-Cmagnetic structure that belongs to type-IV magnetic space groups). A careful study of the magnetic properties around the antiferromagnetic (AFM)-paramagnetic transition yields the critical exponentsβ= 0.309 (0.297),γ= 1.117 (1.038), andδ= 4.617 (4.454), indicating that the tricritical mean field model or the three-dimensional Ising model works for ErIn3's magnetic behaviors and the presence of a long-range AFM interaction therein. Besides, the exchange interaction distanceJ(r) ∼r-4.665as well confirms a long-range magnetic coupling in ErIn3. Our results offer the clues that the magnetic structure varies from one member ofReIn3family to another, and to confirm their electronic features in the AFM phases further experimental and theoretical studies are still desired.

Anisotropic magnetoresistance and electronic features of the candidate topological compound praseodymium monobismuthide

PrBi, a sister member of the rare-earth monopnictide family, is an excellent candidate for studying extreme magnetoresistance and nontrivial topological electronic states. In this study, we perform angular magnetoresistance measurements as well as bulk and surface band structure calculations on this compound. PrBi's magnetoresistance is revealed to be significantly angle-dependent and shows a fourfold symmetry as always observed in the nonmagnetic isostructural counterparts, including LaSb, LaBi, and LuBi. Its angular magnetoresistance can be reproduced well using the semiclassical two-band model. The deduced parameters suggest that PrBi hosts an elongated electron pocket with a mobility anisotropy of ∼3.13 and is slightly uncompensated in its carrier concentration. Our bulk and surface band structure calculations confirm the anisotropic electronic features. Moreover, we reveal that a nodal-line-shaped surface state appears at the X̄ point, and is associated with the quadratic dispersion along the -X̄ direction, and the linear type-I Dirac dispersion along the X̄-M̄ direction. Owing to the type-I Dirac dispersion feature, PrBi could serve as a promising material platform for studying many unexpected physical properties, such as the highly anisotropic transport and valley polarization of electrons.

Study of the Void Structure of PAN Fiber by Small Angle x-ray Scattering and Spline Function

The voids in fibers, especially in wet spun fibers are a major factor of fiber structure which greatly affects the fiber properties. A lot of research has shown that the inner voids and surface imperfections were the main causes of strength decreases. Therefore it is very important to determine the void morphology development in fiber processing in order to obtain high quality as-spun fiber.

In this paper we introduce a new method for the determination of void morphology using small angle x-ray scattering with a spline function method in which the average void size, size distribution and the related scattering power as well is obtained.

[Association between inflammation activity of left atrial epicardial adipose tissue measured by 18F-FDG PET/CT and atrial fibrillation]

Objective: To explore the association between inflammation activity of left atrial epicardial adipose tissue (LA-EAT) measured by ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (¹⁸F-FDG PET/CT) and atrial fibrillation (AF). Methods: A total of 78 patients with AF, who underwent ¹⁸F-FDG PET/CT in the Nuclear Medicine Department of the Third Affiliated Hospital of Soochow University due to abnormally elevated levels of tumor indicators or malignant tumors from March 2018 to December 2019, were enrolled in this retrospective study. According to the examination date of PET/CT and basic characteristics of AF patients (gender, age), a 1∶1 propensity score matching was used to enroll a non-AF control group (78 patients). The maximum standard uptake value of left atrial epicardial tissue (LA-EAT FDG SUV_max) and total EAT volume (V-EAT) were measured by ¹⁸F-FDG PET/CT. Left ventricular ejection fraction (LVEF) and left atrial diameter (LAD) were obtained by echocardiography. Blood lipids and biomarkers of inflammation were measured. The differences of clinical data and EAT-related indicators were compared between the AF group and control group. Logistic multivariate regression analysis was used to determine the related factors of AF. Then the receiver operating characteristic (ROC) curve was used to determine the cutoff value of LA-EAT FDG SUV_max on the diagnosis of AF. Univariate and multivariate logistic regression analysis were used to analyze the relationship between the increase of LA-EAT FDG SUV_max and AF. Results: The age was (66.9±10.2) years and there were 55 males (70.5%) in the AF group. The age was (66.9±8.0) years, and there were 52 males (66.7%) in the control group (both P>0.05). The LAD ((44.2±5.8) mm vs. (35.4±4.4) mm), V-EAT ((122.1±42.0) cm³ vs. (91.6±34.5) cm³), and LA-EAT FDG SUV_max ((1.6±0.3) vs. (1.4±0.2)) values were significantly higher, while LVEF ((60.1±4.7)% vs. (63.9±2.9)%) was lower in the AF group than in the control group (P all<0.001). Multivariate logistic regression analysis showed that LAD (OR=1.340, 95%CI 1.195-1.502), V-EAT (OR=1.016, 95%CI 1.001-1.031), and LA-EAT FDG SUV_max (OR=1.375, 95%CI 1.095-1.723) were positively correlated with AF, LVEF (OR=0.781, 95%CI 0.659-0.926) was negatively correlated with AF(P all<0.05). The area under the ROC curve of LA-EAT FDG SUV_max for diagnosis of AF was 0.680 (95%CI 0.597-0.764, P<0.001), and the best cut-off value was 1.415 with a sensitivity of 65.4% and specificity of 61.5%. After adjusting for high-density lipoprotein cholesterol, LVEF, LAD and V-EAT, LA-EAT FDG SUV_max≥1.415 was independently associated with AF (OR=2.982, 95%CI 1.122-7.926, P=0.010). Conclusions: The inflammatory activity of LA-EAT measured by ¹⁸F-FDG PET/CT is an independent risk factor of AF, and the increased inflammatory activity of LA-EAT is positively correlated with AF.

Coupled electronic and magnetic relaxation in Fe1+yTe: direct evidence for the interaction between itinerant carriers and local moments

Iron chalcogenides are of particular interests among iron-based superconductors due to their distinct properties such as high-T_con FeSe monolayer and competing magnetic correlations in Fe_1+yTe. Here we report unusual transport properties observed near the critical composition of Fe_1+yTe (y∼ 0.09) where competing magnetic correlations exist. The resistivity exhibits surprising temperature-dependent relaxation behavior belowT_N, resulting in the increase of resistivity with time for 35 K <T<T_N, but the decrease of resistivity with time for 10 K <T< 35 K. Such resistivity relaxation is intimately coupled to the magnetization relaxation and can be attributed to the glassy magnetic states induced by the competing magnetic orders. These findings demonstrate strong coupling between itinerant carriers and local ordered moments in Fe_1+yTe.

A Facile and Scalable Method of Fabrication of Large-Area Ultrathin Graphene Oxide Nanofiltration Membrane

With their ultrafast water transport and excellent molecule sieving properties, graphene oxide (GO)-based membranes show great potential in the membrane filtration field for water purification and molecular separation. However, the inability of uniform GO membranes to be produced on an industrial scale and their nonenvironmentally friendly reduction treatment are the bottleneck preventing their industrial applications. Herein, we report a scalable ultrathin uniform GO membrane fabrication technique. Ultrathin GO membranes with a large area of 30 × 80 cm² and a thickness of a few nanometers were uniformly and facilely fabricated using a continuous process combining Mayer rod-coating and a short-time, high-power UV reduction. The interlayer spacing of the GO membrane could be effectively reduced and regulated to improve the salt rejection rate. The fabricated membrane showed superior water permeability of over 60.0 kg m^-2 h^-1 and a high separation efficiency of over 96.0% for a sodium sulfate (Na₂SO₄) solution. It also exhibited excellent mechanical stability under various harsh crossflow conditions. More importantly, the fabrication method developed here can be scaled up using a roll-to-roll industrial production process, which successfully solves the problem currently faced by GO membrane researchers and makes the industrial usage of GO membrane a reality.

Mussel-Inspired Design of a Self-Adhesive Agent for Durable Moisture Management and Bacterial Inhibition on PET Fabric

Functional textiles with advanced moisture management can enhance human comfort and physiological health. However, conventional wet finishing processes used for textiles are usually highly polluting and exhibit poor fastness. Inspired by the strong underwater adhesion properties of mussels based on cation-π interaction, a novel superhydrophilic polymeric molecule with strong cohesion and adhesion property is designed on a poly(ethylene terephthalate) (PET) fabric. The cation-π hydrophilic agent (CPHA) can efficiently transform the hydrophobic PET fabric to a superhydrophilic one, and its superhydrophilicity can withstand 150 home laundry cycles. In addition, the cationic moieties in the CPHA self-adhere to the PET fabric without any finishing auxiliary that would cause pollution. Due to its strong adhesion, CPHA can be applied to one side of the PET fabric via spray coating and curing to form a Janus hydrophobic/superhydrophilic fabric capable of diode-like one-way sweat transportation (with forward transportation capability of 1115% and backward transportation capability of -1509%). Moreover, the Janus fabric inhibits bacterial growth and invasion, while simultaneously preserving the inner ecological healthy balance of the skin's microflora. This work opens up a pathway to develop adhesives in textile wet processing for more diverse, smarter applications, e.g., quick-dry sportswear, protective suits, or air-conditioning fabrics.

Characterization of serum adiponectin and leptin in healthy perinatal dairy cows or cows with ketosis, and their effectson ketosis involved indices

We investigated changes in concentrations of ADP (adiponectin), LEP (leptin), BHBA (beta-hydroxybutyric acid), NEFA (non-esterified fatty acid), Glucose (Glu) and INS (insulin) in serum of healthy perinatal dairy cows and cows with ketosis. Twenty-one healthy cows and seventeen cows with ketosis from a herd of a total 60 Holstein cows (near dry period i.e. 56 days antepartum) were selected. Blood was collected through the tail vein every 7 days, from 56 day antepartum to 56 day postpartum. Serum ADP, LEP, BHBA, NEFA, Glu, and INS concentrations were determined, and ketosis was diagnosed through serum BHBA (≥1.2 mmol/L). We showed the concentration of serum adipokines and energy balancing indices were stable during antepar- tum period. However, ADP concentration increased while LEP decreased, and there were a significant increase in cows with ketosis compared to that of in healthy cows. Serum BHBA and NEFA concentrations increased significantly at first, and then gradually decreased in both healthy cows and cows with ketosis. However, cows with ketosis showed higher concentrations of BHBA and NEFA which restored later. The serum concentration of Glu in both healthy dairy cows and cows with ketosis showed a decreasing trend. INS concentration in healthy cows was decreased while it was increased in cows with ketosis. The results reflect the extent of hypo- glycemia and lipid mobilization postpartum, suggest IR exists in cows with ketosis while serum ADP and LEP might play roles in the development of ketosis.

Endothelium capture-based liver segment imaging using vascular endothelial growth factor receptor 2 in preclinical ex vivo models

BACKGROUND

Near-infrared (NIR) imaging of liver segments provides substantial information for surgeons performing liver resection. It was hypothesized that ramucirumab, an endothelium-specific antibody approved by the Food and Drug Administration, could be used for liver segment imaging using the endothelium capture principle.

METHODS

The capture efficacy of anti-vascular endothelial growth factor receptor (VEGFR) 2 monoclonal antibodies (mAbs) and segment imaging were studied in a mouse model. Binding of ramucirumab in human and porcine tissues was studied using immunofluorescence staining. Isolated porcine liver perfusion was used to analyse the labelling and NIR imaging of selected liver segments.

RESULTS

VEGFR2 is well expressed on the endothelium of the smallest microvascular blood vessels in mouse, porcine and human liver tissues, as well as in human liver tumours. Perfusion of selected segments in the isolated liver model showed high capture of the anti-VEGFR2 (clone 522302) mAb and ramucirumab in mice and pigs respectively. NIR imaging of selected segments was achieved using isolated porcine liver perfusion with IRDye® 800CW-conjugated ramucirumab.

CONCLUSION

VEGFR2 is well expressed on the smallest microvascular blood vessels and can capture antibodies during single intravascular passages with high efficacy. The ex vivo imaging of a selected segment using endothelial capture of ramucirumab demonstrates the potential of this antibody for intraoperative navigation in liver surgery. Surgical relevance Imaging of liver segments provides substantial information for surgeons when performing liver resection. The antivascular endothelial growth factor receptor (VEGFR) 2 antibody ramucirumab conjugated with near-infrared dye could visualize selected liver segments using an endothelial capture-based approach in an isolated perfusion liver model. The ex vivo imaging of a selected segment using endothelial capture of ramucirumab demonstrates the potential of this anti-VEGFR2 antibody for intraoperative navigation in liver surgery.

LncRNA H19 serves as a ceRNA and participates in non-small cell lung cancer development by regulating microRNA-107

OBJECTIVE

To investigate whether lncRNA H19 can regulate NF1 expression through competitive binding to microRNA-107, thereby participating in the occurrence and development of non-small cell lung cancer (NSCLC).

PATIENTS AND METHODS

Expression levels of H19 and NF1 in NSCLC tissues, paracancerous tissues and NSCLC cell lines were detected by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR). The binding condition of microRNA-107, H19 and NF1 was detected by dual-luciferase reporter gene assay. Corresponding lentiviruses of H19 were constructed. The regulatory effects of H19 on proliferative and migratory abilities of A549 cells were detected by cell counting kit-8 (CCK-8) and transwell assay, respectively. Rescue experiments were conducted to explore the regulatory interaction between H19 and microRNA-107 in A549 cells.

RESULTS

H19 and NF1 were highly expressed in NSCLC tissues and NSCLC cell lines (A549 and HCC823) than those of controls. Overexpressed H19 increased proliferative and migratory abilities of A549 cells. Dual-luciferase reporter gene assay demonstrated that H19 regulates NF1 expression through competitive binding to microRNA-107, thereafter participating in NSCLC development.

CONCLUSIONS

H19 is highly expressed in NSCLC, which promotes NSCLC development by regulating NF1 via competitive binding to microRNA-107.

[Association of polycyclic aromatic hydrocarbon exposure and CYP1A1 gene and enzyme activity of peripheral blood monocyte cells in coke oven workers]

Objective: To explore the association between polycyclic aromatic hydrocarbons (PAHs) exposure and cytochrome P450 CYP1A1 expression at gene and enzyme activity levels in the peripheral blood monocyte cells in coke oven workers, and to provide a certain basis for the biological monitoring of health damage in coke oven workers. Methods: We surveyed 118 coke oven workers and 63 controls (energy power workers in the same company) using self-designed questionnaire, determined their post-shift urinary 1-hydroxypyrene (1-OH-Py) concentration using high performance liquid chromatography (HPLC)-fluorescence detector method. We also isolated the peripheral blood mononuclear cell (PBMC) from fasting venous blood, and detected DNA damage using comet assay, CYP1A1 mRNA level using the real-time fluorescent quantitative PCR (FQ-PCR), and EROD activity using spectrophotometry. Statistical analyses including one-way analysis of variance and multiple linear regressions were used to analyze the association of urinary 1-OH-Py and CYP1A1 mRNA level and EROD activity. Results: Compared to the control group, the urinary 1-OH-Py concentration and PBMC DNA tail moment were significantly increased in coke oven workers (P<0.05), and CYP1A1 gene level and EROD activity in PBMC were significantly decreased (P<0.05). Multiple linear regression showed that a ten-fold increase of urinary 1-OH-Pycon centration was associated with a decrease of 0.77 (95%CI: -1.33--0.21) in CYP1A1 gene level, and a decline of 0.15 (95%CI: -0.76--0.16) in EROD activity of PBMC in coke oven workers (P<0.05). Conclusion: Occupational PAHs exposure induced DNA damage, which was associated with the decreased level in CYP1A1 gene cavel and EROD activity in PBMC of coke oven workers.

[Expression of PD-1 and PD-L1 in the peripheral blood of advanced non-small-cell lung cancer patients and its implications]

Objective: To investigate the expression of programmed death 1(PD-1) and programmed death ligand 1 (PD-L1) on T lymphocyte and monocyte from peripheral blood of advanced non-small-cell lung cancer (NSCLC) patients and its potential role in immune escape of NSCLC. Methods: Forty-eight patients with advanced NSCLC (Lung Cancer Group) were included from the Department of Respiratory Diseases in The Second Affiliated Hospital of Soochow University from June 2014 to June 2015. Thirty-six healthy volunteers who received health examination at the same time, matching in sex, age were also enrolled as controls. The expression of PD-1 on peripheral blood CD4(+)T cells and CD8(+)T cells and PD-L1 on monocytes were detected by flow cytometry. Patients who received chemotherapy alone for 2-4 cycles and received sequential sampling were assessed with Response Evaluation Criteria in Solid Tumors 1.1 (RECIST 1.1). Seven cases of patients with significant response to treatment were selected as partial response (PR) group and ten patients with poor response to treatment were treated as progression disease(PD) group. The differences in the expression of PD-1 on the surface of CD4(+)T cells, CD8(+)T cells, and PD-L1 on the surface of monocyte before and after treatment were analyzed. Results: Compared with healthy control group, PD-1 expression level on both CD4(+) T and CD8(+) T cells from peripheral blood in lung cancer group were significantly increased [(25.9±7.4)% vs (20.6±6.2)%, (19.9±9.8)% vs (14.0±5.6)%, both P<0.05]. A higher level of PD-L1 expression on monocyte in lung cancer group was also found compared with the control group [(33.1±15.1)% vs (13.6±5.3)%, P<0.001]. The expression level of PD-1 on CD4(+)T and CD8(+)T cells and PD-L1 on monocytes in lung cancer group with good response to treatment was relatively lower than the baseline level of before treatment [(22.8±8.5)% vs (25.9±7.8)%, (17.1±8.4)% vs (20.4±8.6)%, (18.1±6.9)% vs (31.3±13.2)%, all P<0.05], but in lung cancer group with poor response to treatment, it was higher than the baseline level of before treatment [(33.5±6.5)% vs (23.9±4.2)%, (25.2±9.1)% vs (19.1±8.8)%, (43.1±18.3)% vs (29.7±10.6)%, all P<0.05]. Conclusion: Abnormal expression of PD-1 and PD-L1 exists in T cells and monocytes respectively, prompting PD-1/PD-L1 pathway may inhibit T cell proliferation during the interaction of T cell and monocyte, which may lead to non-small cell lung cancer immune escape.

Climate change impacts on crop yield, soil water balance and nitrate leaching in the semiarid and humid regions of Canada

The impact of climate change on agricultural systems is a major concern as it can have a significant effect on the world food supply. The objective of this study was to evaluate climate change impacts on crop production and nitrate leaching in two distinct climatic zones in Canada. Spring wheat (Triticum aestivum L.) was selected for the semiarid regions of Western Canada (Swift Current, SK) and maize (Zea mays L.) was chosen for the more humid regions of central Canada (Woodslee, ON). Climate scenarios were based upon simulations from a Canadian Regional Climate Model (CanRCM4) under two Representative Concentration Pathways (RCP4.5 and RCP8.5) and crop simulations were conducted using the Decision Support System for Agrotechnology Transfer (DSSAT) model. Compared to the baseline climate scenario, wheat yields increased by 8, 8, 11, 15%, whereas maize yields decreased by 15, 25, 22, 41% under RCP4.5 2050s (2041-2070), RCP4.5 2080s (2071-2100), RCP8.5 2050s and RCP8.5 2080s scenarios, respectively. Annual nitrate leaching increased by 19, 57, 73, 129% at Swift Current and by 84, 117, 208, 317% at Woodslee under the four scenarios, respectively. Adaptation measures suggested that fertilizer N rate for spring wheat should be increased to 80-100 kg N ha-1 to obtain optimal yields although this will result in an additional risk of 5-8 kg N ha-1 nitrate leaching at Swift Current. The fertilizer N rate of 150 kg N ha-1 was found to be suitable for high maize yields at Woodslee. New wheat and maize cultivars with long growing seasons would enable crop growth to match the phenological stage and hence maintain high crop yields to adapt to increased temperatures in the future.

Predicted final spinal height in patients with adolescent idiopathic scoliosis can be achieved by surgery regardless of maturity status

AIMS

The aim of this study was to investigate the impact of maturity status at the time of surgery on final spinal height in patients with an adolescent idiopathic scoliosis (AIS) using the spine-pelvic index (SPI). The SPI is a self-control ratio that is independent of age and maturity status.

PATIENTS AND METHODS

The study recruited 152 female patients with a Lenke 1 AIS. The additional inclusion criteria were a thoracic Cobb angle between 45° and 70°, Risser 0 to 1 or 3 to 4 at the time of surgery, and follow-up until 18 years of age or Risser stage 5. The patients were stratified into four groups: Risser 0 to 1 and selective fusion surgery (Group 1), Risser 0 to 1 and non-selective fusion (Group 2), Risser 3 to 4 and selective fusion surgery (Group 3), and Risser 3 to 4 and non-selective fusion (Group 4). The height of spine at follow-up (HOS_f) and height of pelvis at follow-up (HOP_f) were measured and the predicted HOS (pHOS) was calculated as 2.22 (SPI) × HOP_f. One-way analysis of variance (ANOVA) was performed for statistical analysis.

RESULTS

Of the 152 patients, there were 32 patients in Group 1, 27 patients in Group 2, 48 patients in Group 3, and 45 patients in Group 4. Significantly greater HOS_f was observed in Group 3 compared with Group 1 (p = 0.03) and in Group 4 compared with Group 2 (p = 0.02), with similar HOP_f (p = 0.75 and p = 0.83, respectively), suggesting that patients who undergo surgery at Risser grade of 0 to 1 have a shorter spinal height at follow-up than those who have surgery at Risser 4 to 5. HOS_f was similar to pHOS in both Group 1 and Group 2 (p = 0.62 and p = 0.45, respectively), indicating that undergoing surgery at Risser 0 to 1 does not necessarily affect final spinal height.

CONCLUSION

This study shows that fusion surgery at Risser 0 may result in growth restriction unlike fusion surgery at Risser 3 to 4. Despite such growth restriction, AIS patients could reach their predicted or 'normal' spinal height after surgery regardless of baseline maturity status due to the longer baseline spinal length in AIS patients and the remaining growth potential at the non-fusion levels. Cite this article: Bone Joint J 2018;100-B:1372-6.

Abstract P5-07-03: Withdrawn

This abstract was withdrawn by the authors.

Evidence of s-wave superconductivity in the noncentrosymmetric La7Ir3

Superconductivity in noncentrosymmetric compounds has attracted sustained interest in the last decades. Here we present a detailed study on the transport, thermodynamic properties and the band structure of the noncentrosymmetric superconductor La 7 Ir 3 (T c  ~ 2.3 K) that was recently proposed to break the time-reversal symmetry. It is found that La7Ir3 displays a moderately large electronic heat capacity (Sommerfeld coefficient γ n  ~ 53.1 mJ/mol K2) and a significantly enhanced Kadowaki-Woods ratio (KWR ~32 μΩ cm mol2 K2 J-2) that is greater than the typical value (~10 μΩ cm mol2 K2 J-2) for strongly correlated electron systems. The upper critical field Hc2 was seen to be nicely described by the single-band Werthamer-Helfand-Hohenberg model down to very low temperatures. The hydrostatic pressure effects on the superconductivity were also investigated. The heat capacity below T c reveals a dominant s-wave gap with the magnitude close to the BCS value. The first-principles calculations yield the electron-phonon coupling constant λ = 0.81 and the logarithmically averaged frequency ω ln  = 78.5 K, resulting in a theoretical T c  = 2.5 K, close to the experimental value. Our calculations suggest that the enhanced electronic heat capacity is more likely due to electron-phonon coupling, rather than the electron-electron correlation effects. Collectively, these results place severe constraints on any theory of exotic superconductivity in this system.

Flexible Slippery Surface to Manipulate Droplet Coalescence and Sliding, and Its Practicability in Wind-Resistant Water Collection

A flexible slippery membrane (FSM) with tunable morphology and high elastic deformability has been developed by infusing perfluoropolyether (PFPE) into a fluorinated-copolymer-modified thermoplastic polyurethane (TPU) nanofiberous membrane. To immobilize PFPE in TPU matrix, we synthesized a fluorinated-copolymer poly(DFMA-co-IBOA-co-LMA) with low surface energy, high chemical affinity to PFPE, adequate flexibility, and strong physical adhesion on TPU. Upon external tensile stress, the as-prepared FSM can realize a real-time manipulation of water sliding and coalescence on it. Furthermore, it exhibits the ability to preserve the captured water from being blown away by strong wind, which ensures the water collection efficiency in windy regions.

A thermal protective urethral heater applied to modulate the prostate cryoablation area

BACKGROUND

Urethral warmer and cryoheater are invented and applied in cryoablation to overcome urethral cryoinjury, but these devices cannot be fixed and precisely control the released heat which excessively reduces the effective ablation area. Current warmers enlarge the operation difficulty and decrease the precision in temperature control.

OBJECTIVE

A reformed catheter termed urethral heater aims to protect the urethra and simultaneously control the released heat so as to meet the aid of doctors' convenient operation in effective therapy, device fixation and precise heat controllability.

MATERIALS AND METHODS

In this paper, the temperature controller combined with temperature monitor was used to control the heating behavior of the urethral heater with the initial active temperature. The controllability and thermal protection of the urethral heater was simulated and tested, which compared with that of urethral warmer.

RESULTS

During the trials in vitro, the lowest temperature at the urethra surface is -3.7 degree C when one cryoprobe was introduced in the cryoablation for 15 min and -15.3 degree C with two cryoprobes. Above all, the effective cryoablation area increased with the decline of initial active temperatures.

CONCLUSION

The urethral heater is able to prevent the urethra from irreversible damage and modulate the ablation area. The delay of heat is a new way to decline the recurrence rate and facilitate the desire of aconuresis during the cryoablation.

Intermartensitic Transformation and Enhanced Exchange Bias in Pd (Pt) -doped Ni-Mn-Sn alloys

In this work, we studied the phase transitions and exchange bias of Ni_50−xMn₃₆Sn₁₄T_x (T = Pd, Pt; x = 0, 1, 2, 3) alloys. An intermartensitic transition (IMT), not observed in Ni₅₀Mn₃₆Sn₁₄ alloy, was induced by the proper application of negative chemical pressure by Pd(Pt) doping in Ni_50−xMn₃₆Sn₁₄T_x (T = Pd, Pt) alloys. IMT weakened and was suppressed with the increase of applied field; it also disappeared with further increase of Pd(Pt) content (x = 3 for Pd and x = 2 for Pt). Another striking result is that exchange bias effect, ascribed to the percolating ferromagnetic domains coexisting with spin glass phase, is notably enhanced by nonmagnetic Pd(Pt) addition. The increase of unidirectional anisotropy by the addition of Pd(Pt) impurities with strong spin-orbit coupling was explained by Dzyaloshinsky-Moriya interactions in spin glass phase.

Magnetic manipulation of electric orders in Co4NbTaO9

Magnetic, dielectric and magnetoelectric properties of the polycrystalline Co₄NbTaO₉ have been investigated in this paper.

Modulated multiferroic properties of MnWO4via chemical doping

Here we prepare polycrystalline Mn_1−xNi_xWO₄ ceramics with x = 0, 0.02, 0.04, 0.06 for investigating their magnetic, ferroelectric, and multiferroic properties.

Defects-tolerant Co-Cr-Mo dental alloys prepared by selective laser melting

OBJECTIVES

CrCoMo alloy specimens were successfully fabricated using selective laser melting (SLM). The aim of this study was to carefully investigate microstructure of the SLM specimens in order to understand the influence of their structural features inter-grown on different length scales ranging from nano- to macro-levels on their mechanical properties.

METHODS

Two different sets of processing parameters developed for building the inner part (core) and the surface (skin) of dental prostheses were tested. Microstructures were characterized by SEM, EBSD and XRD analysis. The elemental distribution was assessed by EDS line profile analysis under TEM. The mechanical properties of the specimens were measured.

RESULTS

The microstructures of both specimens were characterized showing formation of grains comprised of columnar sub-grains with Mo-enrichment at the sub-grain boundaries. Clusters of columnar sub-grains grew coherently along one common crystallographic direction forming much larger single crystal grains which are intercrossing in different directions forming an overall dendrite-like microstructure. Three types of microstructural defects were occasionally observed; small voids (<10 μm), fine cracks at grain boundaries (<10 μm) and cracks at weld line boundaries (>10 μm). Despite the presence of these defects, the yield and the ultimate tensile strength (UTS) were 870 and 430MPa and 1300MPa and 1160MPa, respectively, for the skin and core specimens which are higher than casted dental alloy.

SIGNIFICANCE

Although the formation of microstructural defects is hard to be avoided during the SLM process, the SLM CoCrMo alloys can achieve improved mechanical properties than their casted counterparts, implying they are "defect-tolerant".

Primary fallopian tube carcinoma--a retrospective analysis of 66 cases

BACKGROUND

Primary fallopian tube carcinoma (PFTC) is a rare malignant gynecologic oncology. There was no consensus on the outcome related clinicopathological characteristics. Present study aims to determine the prognosis associate factors in PFTC.

MATERIALS AND METHODS

In this retrospective study, the authors identified 50 PFTC patients in Jiangsu Institute of Cancer Research and 16 cases in the Affiliated People's Hospital of Inner Mongolia Medical College between 1988 and 2013. Disease surveillance was conducted based on the follow-up protocol of MD Anderson Cancer Center. Cox proportional hazards model and log-rank test were used to assess the associations between potential clinicpathologic characteristics and the survival durations.

RESULTS

The median progression free survival (PFS) and overall survival (OS) of PFTC were 36.9 and 62.7 months, respectively. FIGO Stage (p < 0.01, 0.01), grade (p = 0.02, 0.03), tumor residual after initial debulking surgery (p = 0.05, 0.01), nadir CA-125 (p = 0.01, 0.01) were independently related with PFS and OS. The PFS and OS of patients with Stage II PFTC were similar as those with Stage III-IV (30.7 vs 28.3 and 61.9 vs 49.2 months, respectively) but poorer than those of Stage I cases (N/A). The PFS of patients with paclitaxel-based chemotherapy was longer than those with other regime (51.3 vs 33.1 months), but not OS (62.7 vs 42.6 months). The outcome of patients underwent optimal initial cytoreduction surgery was better than those of suboptimal ones (PFS 56.4 vs 21.2 months and OS 65.3 vs 47.9 months, respectively). CONCLUSIOn: PFTC patients with FIGO Stage II disease should be regarded as advanced disease. Paclitaxel based chemotherapy was associated with longer PFS but not OS in PFTC.

Up-regulation of microRNA-183-3p is a potent prognostic marker for lung adenocarcinoma of female non-smokers

BACKGROUND

Lung cancer in never smokers presents predominately as adenocarcinoma and in females. MicroRNA-183 (miR-183) has various expression patterns in types of human cancers. In the present study, we evaluated the expression of miR-183-3p in female lung adenocarcinoma and adjacent noncancerous tissues and explored its relationship with clinicopathological characteristics and prognosis.

METHODS

In the present study, a hundred female nonsmoking patients who were newly diagnosed and histologically confirmed as lung adenocarcinoma at Tianjin Medical University Cancer Hospital were included. miR-183-3p expression of surgically removed NSCLC tissues and their corresponding normal lung tissues was measured by qRT-PCR assay. Associations of miR-183-3p expression with clinicopathological features were determined using the Student's t test. Log-rank test, and Cox proportional hazards model were used for survival analysis.

RESULTS

At first, miR-183-3p was up-regulated in lung cancer tissues when compared with the corresponding noncancerous lung tissues. Moreover, the expression of miR-183-3p in tumor tissue was found to be associated with lymph node metastasis (P = 0.043), clinical stage (P = 0.015), and EGFR mutation (P = 0.003). At last, high miR-183-3p expression was also associated with both poor overall survival and progression-free survival of women with lung adenocarcinoma (P = 0.005 and P = 0.010, respectively).

CONCLUSION

This study suggested that miR-183-3p expression might be involved in lung cancer pathogenesis and progression, and could be used as a potential prognostic biomarker of female lung adenocarcinoma.

Friedel-like oscillations from interstitial iron in superconducting Fe(1+y)Te0.62Se0.38

Using polarized and unpolarized neutron scattering, we show that interstitial Fe in superconducting Fe(1+y)Te(1-x)Se(x) induces a magnetic Friedel-like oscillation that diffracts at Q⊥=(1/2 0) and involves >50 neighboring Fe sites. The interstitial >2μ(B) moment is surrounded by compensating ferromagnetic four-spin clusters that may seed double stripe ordering in Fe(1+y)Te. A semimetallic five-band model with (1/2 1/2) Fermi surface nesting and fourfold symmetric superexchange between interstitial Fe and two in-plane nearest neighbors largely accounts for the observed diffraction.

The effects of lesions in the dorsolateral pons on the coordination of swallowing and breathing in awake goats

The purpose of this retrospective study was to gain insight into the contribution of the dorsolateral pons to the coordination of swallowing and breathing in awake goats. In 4 goats, cannulas were chronically implanted bilaterally through the lateral (LPBN) and medial (MPBN) parabrachial nuclei just dorsal to the Kölliker-Fuse nucleus (KFN). After >2weeks recovery from this surgery, the goats were studied for 5½h on a control day, and on separate days after receiving 1 and 10μl injections of ibotenic acid (IA) separated by 1week. The frequency of swallows did not change during the control and 1μl IA studies, but after injection of 10μl IA, there was a transient 65% increase in frequency of swallows (P<0.05). Under control conditions swallows occurred throughout the respiratory cycle, where late-E swallows accounted for 67.6% of swallows. The distribution of swallow occurrence throughout the respiratory cycle was unaffected by IA injections. Consistent with the concept that swallowing is dominant over breathing, we found that swallows increased inspiratory (T(I)) and expiratory (T(E)) time and decreased tidal volume (V(T)) of the breath of the swallow (n) and/or the subsequent (n+1) breath. Injections of 10μl IA attenuated the normal increases in T(I) and T(E) and further attenuated V(T) of the n breath. Additionally, E and I swallows reset respiratory rhythm, but injection of 1 or 10μl IA progressively attenuated this resetting, suggesting a decreased dominance over respiratory motor output with increasing IA injections. Post mortem histological analysis revealed about 50% fewer (P<0.05) neurons remained in the KFN, LPBN, and MPBN in lesioned compared to control goats. We conclude that dorsolateral pontine nuclei have a modulatory role in a hypothesized holarchical neural network regulating swallowing and breathing particularly contributing to the normal dominance of swallowing over breathing in both rhythm and motor pattern generation.

From (pi,0) magnetic order to superconductivity with (pi,pi) magnetic resonance in Fe(1.02)Te(1-x)Se(x)

The iron chalcogenide Fe(1+y)(Te(1-x)Se(x)) is structurally the simplest of the Fe-based superconductors. Although the Fermi surface is similar to iron pnictides, the parent compound Fe(1+y)Te exhibits antiferromagnetic order with an in-plane magnetic wave vector (pi,0) (ref. 6). This contrasts the pnictide parent compounds where the magnetic order has an in-plane magnetic wave vector (pi,pi) that connects hole and electron parts of the Fermi surface. Despite these differences, both the pnictide and chalcogenide Fe superconductors exhibit a superconducting spin resonance around (pi,pi) (refs 9, 10, 11). A central question in this burgeoning field is therefore how (pi,pi) superconductivity can emerge from a (pi,0) magnetic instability. Here, we report that the magnetic soft mode evolving from the (pi,0)-type magnetic long-range order is associated with weak charge carrier localization. Bulk superconductivity occurs as magnetic correlations at (pi,0) are suppressed and the mode at (pi, pi) becomes dominant for x>0.29. Our results suggest a common magnetic origin for superconductivity in iron chalcogenide and pnictide superconductors.

Anatomic changes in multiple brainstem nuclei after incremental, near-complete neurotoxic destruction of the pre-Bötzinger Complex in adult goats

Abrupt, bilateral destruction of the pre-Bötzinger Complex (preBötC) leads to terminal apnea in unanesthetized goats and rats. In contrast, respiratory rhythm and pattern and arterial blood gases in goats during wakefulness and sleep are normal after incremental (over a month) destruction of > 90% of the preBötC. Here, we tested the hypothesis that the difference in effects between abrupt and incremental destruction of the preBötC are a result of time-dependent plasticity, which manifests as anatomic changes at sites within the respiratory network. Accordingly, we report data from histological analyses comparing the brainstems of control goats, and goats that had undergone bilateral, incremental, ibotenic acid (IA)-induced preBötC lesioning. A major focus was on the parafacial respiratory group/retrotrapezoid nucleus (pFRG/RTN) and the pontine respiratory group (PRG), which are sites thought to contribute to respiratory rhythmogenesis. We also studied the facial (FN), rostral nucleus ambiguus (NA), medullary raphé (MRN), hypoglossal (HN), and the dorsal motor vagal (DMV) nuclei. Neuronal counts, count region area (mm²), and neuronal densities were calculated using computer-assisted analyses and/or manual microscopy to compare control and preBötC-lesioned animals. We found that within the ventral and lateral medulla 2mm rostral to the caudal pole of the FN (presumed pFRG/RTN), there were 25% and 65% more (P < 0.001) neurons, respectively, in preBötC-lesioned compared to control goats. Lesioned goats also showed 14% and 13% more (P < 0.001) neurons in the HN and medial parabrachialis nucleus, but 46%, 28%, 7%, and 17% fewer (P < 0.001) neurons in the FN, NA, DMV, and Kölliker-Fuse nuclei, respectively. In the remaining sites analyzed, there were no differences between groups. We conclude that anatomic changes at multiple sites within the respiratory network may contribute to the time-dependent plasticity in breathing following incremental and near-complete destruction of the preBötC.

The pontine respiratory group, particularly the Kölliker-Fuse nucleus, mediates phases of the hypoxic ventilatory response in unanesthetized goats

The objective of the present study was to test the hypothesis that, in the in vivo awake goat model, perturbation/lesion in the pontine respiratory group (PRG) would decrease the sensitivity to hypercapnia and hypoxia. The study reported herein was part of two larger studies in which cholinergic modulation in the PRG was attenuated by microdialysis of atropine and subsequently ibotenic acid injections neurotoxically lesioned the PRG. In 14 goats, cannula were bilaterally implanted into either the lateral (n=4) or medial (n=4) parabrachial nuclei or the Kölliker-Fuse nucleus (KFN, n=6). Before and after cannula implantation, microdialysis of atropine, and injection of ibotenic acid, hypercapnic and hypoxic ventilatory sensitivities were assessed. Hypercapnic sensitivity was assessed by three 5-min periods at 3, 5, and 7% inspired CO2. In all groups of goats, CO2 sensitivity was unaffected (P>0.05) by any PRG perturbations/lesions. Hypoxic sensitivity was assessed with a 30-min period at 10.8% inspired O2. The response to hypoxia was typically triphasic, with a phase 1 increase in pulmonary ventilation, a phase 2 roll-off, and a phase 3 prolonged increase associated with shivering and increased metabolic rate and body temperature. In all groups of goats, the phase 1 of the hypoxic ventilatory responses was unaffected by any PRG perturbations/lesions, and there were no consistent effects on the phase 2 responses. However, in the KFN group of goats, the phase 3 ventilatory, shivering, metabolic rate, and temperature responses were markedly attenuated after the atropine dialysis studies, and the attenuation persisted after the ibotenic acid studies. These findings support an integrative or modulatory role for the KFN in the phase 3 responses to hypoxia.

A role for the Kolliker-Fuse nucleus in cholinergic modulation of breathing at night during wakefulness and NREM sleep

For many years, acetylcholine has been known to contribute to the control of breathing and sleep. To probe further the contributions of cholinergic rostral pontine systems in control of breathing, we designed this study to test the hypothesis that microdialysis (MD) of the muscarinic receptor antagonist atropine into the pontine respiratory group (PRG) would decrease breathing more in animals while awake than while in NREM sleep. In 16 goats, cannulas were bilaterally implanted into rostral pontine tegmental nuclei (n = 3), the lateral (n = 3) or medial (n = 4) parabrachial nuclei, or the Kölliker-Fuse nucleus (KFN; n = 6). After >2 wk of recovery from surgery, the goats were studied during a 45-min period of MD with mock cerebrospinal fluid (mCSF), followed by at least 30 min of recovery and a second 45-min period of MD with atropine. Unilateral and bilateral MD studies were completed during the day and at night. MD of atropine into the KFN at night decreased pulmonary ventilation and breathing frequency and increased inspiratory and expiratory time by 12-14% during both wakefulness and NREM sleep. However, during daytime studies, MD of atropine into the KFN had no effect on these variables. Unilateral and bilateral nighttime MD of atropine into the KFN increased levels of NREM sleep by 63 and 365%, respectively. MD during the day or at night into the other three pontine sites had minimal effects on any variable studied. Finally, compared with MD of mCSF, bilateral MD of atropine decreased levels of acetylcholine and choline in the effluent dialysis fluid. Our data support the concept that the KFN is a significant contributor to cholinergically modulated control of breathing and sleep.

Site-specific effects on respiratory rhythm and pattern of ibotenic acid injections in the pontine respiratory group of goats

To probe further the contributions of the rostral pons to eupneic respiratory rhythm and pattern, we tested the hypothesis that ibotenic acid (IA) injections in the pontine respiratory group (PRG) would disrupt eupneic respiratory rhythm and pattern in a site- and state-specific manner. In 15 goats, cannulas were bilaterally implanted into the rostral pontine tegmental nuclei (RPTN; n = 3), the lateral (LPBN; n = 4) or medial parabrachial nuclei (MPBN; n = 4), or the Kölliker-Fuse nucleus (KFN; n = 4). After recovery from surgery, 1- and 10-microl injections (1 wk apart) of IA were made bilaterally through the implanted cannulas during the day. Over the first 5 h after the injections, there were site-specific ventilatory effects, with increased (P < 0.05) breathing frequency in RPTN-injected goats, increased (P < 0.05) pulmonary ventilation (Vi) in LPBN-injected goats, no effect (P < 0.05) in MPBN-injected goats, and a biphasic Vi response (P < 0.05) in KFN-injected goats. This biphasic response consisted of a hyperpnea for 30 min, followed by a prolonged hypopnea and hypoventilation with marked apneas, apneusis-like breathing patterns, and/or shifts in the temporal relationships between inspiratory flow and diaphragm activity. In the awake state, 10-15 h after the 1-microl injections, the number of apneas was greater (P < 0.05) than during other studies at night. However, there were no incidences of terminal apneas. Breathing rhythm and pattern were normal 22 h after the injections. Subsequent histological analysis revealed that for goats with cannulas implanted into the KFN, there were nearly 50% fewer neurons (P < 0.05) in all three PRG subnuclei than in control goats. We conclude that in awake goats, 1) IA injections into the PRG have site-specific effects on breathing, and 2) the KFN contributes to eupneic respiratory pattern generation.

Excitation mapping of whispering gallery modes in silica microcavities

We report the direct observation of the electromagnetic-field distribution of whispering gallery modes in silica microcavities (spheres and toroids). It is revealed by their excitation efficiency with a tapered fiber coupler swept along the meridian. The originality of this method lies in the use of the coupler itself for the near-field mapping, eliminating the need of additional tools used in previous work. This method is successfully applied to microspheres and microtoroids.

Robust hairy microspheres and derived hairy surfaces by an "inside-out" wet approach

Robust hairy microspheres were conveniently synthesized through an "inside-out" protrusion approach consisting of a sol-gel reaction and a radical polymerization, from conventional organosilanes and vinyl monomers. Their hierarchical structures of hard cores and plastic hairs can be adjusted in terms of their sizes and compositions to impart various chemical and physical properties on their surfaces. These hairy microspheres can also be built into hairy surfaces with many useful functions, such as superhydrophobicity. This work opens up a new route for the synthesis of hierarchical particles and enriches the tool library of material and surface engineering.

Differences between three inbred rat strains in number of K+ channel-immunoreactive neurons in the medullary raphé nucleus

Ventilatory sensitivity to hypercapnia is greater in Dahl salt-sensitive (SS) rats than in Fawn Hooded hypertensive (FHH) and Brown Norway (BN) inbred rats. Since pH-sensitive potassium ion (K(+)) channels are postulated to contribute to the sensing and signaling of changes in CO(2)-H(+) in chemosensitive neurons, we tested the hypothesis that there are more pH-sensitive K(+) channel-immunoreactive (ir) neurons within the medullary raphé nuclei of the highly chemosensitive SS rats than in the other two strains. Medullary tissues from male and female BN, FHH, and SS rats were stained with cresyl violet or with antibodies targeting TASK-1, K(v)1.4, and Kir2.3 channels. K(+) channel-ir neurons were quantified and compared with the total neurons in the region. The total number of neurons in the medullary raphé 1) was greater in male FHH than the other male rats, 2) did not differ among the female rats, and 3) did not differ between sexes. The average number of K(+) channel-ir neurons per section was 30-60 neurons higher in the male SS than in the other rat strains. In contrast, for the females, the number of K(+) channel-ir neurons was greatest in the BN. We also found significant differences in the number of K(+) channel-ir neurons between sexes in SS (males > females) and BN (females > males) rats, but not the FHH strain. Our findings support the hypothesis for males but not for females, suggesting that both genetic background and sex are determinants of K(+) channel immunoreactivity of medullary raphé neurons, and that the expression of pH-sensitive K(+) channels in the medullary raphé does not correlate with the ventilatory sensitivity to hypercapnia.

Micro-opioid receptor agonist injections into the presumed pre-Botzinger complex and the surrounding region of awake goats do not alter eupneic breathing

Opioids are clinically important in the alleviation of pain. An undesirable side effect of opioids is depression of breathing. Data from isolated preparations suggest this effect is due to attenuation of discharge activity of neurons in the pre-Bötzinger complex (preBötzC), a medullary area with respiratory rhythmogenic properties. The purpose of this study was to examine how [d-Ala(2),N-Me-Phe(4),Gly(5)-ol]-enkephalin (DAMGO), a mu-opioid receptor agonist, affected breathing after injection into the presumed preBötzC of the adult awake goat. We hypothesized that DAMGO would cause breathing to decrease and become irregular when injected into the presumed preBötzC and the surrounding region of the conscious animal. We further hypothesized that ventilatory sensitivity to CO(2) and hypoxia would be blunted after the injection of DAMGO. Microtubules were bilaterally implanted into the presumed preBötzC of 10 adult female goats. After recovery from the surgery, DAMGO (0.5-10 mul, 1 nM-10 muM) was injected into the presumed preBötzC during the awake state. DAMGO had no effect on pulmonary ventilation [inspiratory minute ventilation (Vi)], respiratory rhythm and pattern, the activation pattern of inspiratory and expiratory muscles, or arterial blood gases during eupneic breathing conditions (P > 0.10). However, DAMGO attenuated (P < 0.05) the evoked increase in breathing frequency when inspired CO(2) was increased, and DAMGO attenuated the Vi response to reduction of inspired O(2) to 10.8% (P < 0.05). We conclude that our data do not provide support for the concept that in awake mammals opioid depression of breathing is due to a directed action of opioids on preBötzC neurons.

Tunable (deltapi, deltapi)-type antiferromagnetic order in alpha-Fe(Te,Se) superconductors

The new alpha-Fe(Te,Se) superconductors share the common iron building block and ferminology with the LaFeAsO and BaFe(2)As(2) families of superconductors. In contrast with the predicted commensurate spin-density-wave order at the nesting wave vector (pi, 0), a completely different magnetic order with a composition tunable propagation vector (deltapi, deltapi) was determined for the parent compound Fe_{1+y}Te in this powder and single-crystal neutron diffraction study. The new antiferromagnetic order survives as a short-range one even in the highest T_{C} sample. An alternative to the prevailing nesting Fermi surface mechanism is required to understand the latest family of ferrous superconductors.

Normal breathing pattern and arterial blood gases in awake and sleeping goats after near total destruction of the presumed pre-Botzinger complex and the surrounding region

Abrupt neurotoxic destruction of >70% of the pre-Bötzinger complex (preBötzC) in awake goats results in respiratory and cardiac failure (Wenninger JM, Pan LG, Klum L, Leekley T, Bastastic J, Hodges MR, Feroah TR, Davis S, Forster HV. J Appl Physiol 97: 1629-1636, 2004). However, in reduced preparations, rhythmic respiratory activity has been found in other areas of the brain stem (Huang Q, St. John WM. J Appl Physiol 64: 1405-1411, 1988; Janczewski WA, Feldman JL. J Physiol 570: 407-420, 2006; Lieske SP, Thoby-Brisson M, Telgkamo P, Ramierz JM. Nature Neurosci 3: 600-607, 2000; St. John WM, Bledsoe TA. J Appl Physiol 59: 684-690, 1985); thus we hypothesized that, when the preBötzC is destroyed incrementally over weeks, time-dependent plasticity within the respiratory network will result in a respiratory rhythm capable of maintaining normal blood gases. Microtubules were bilaterally implanted into the presumed preBötzC of seven goats. After recovery from surgery, studies were completed to establish baseline values for respiratory parameters. At weekly intervals, increasing volumes (in order 0.5, 1, 5, and 10 microl) of ibotenic acid (IA; 50 mM) were then injected into the preBötzC. All IA injections resulted in an acute tachypnea and dysrhythmia featuring augmented breaths, apneas, and increased breath-to-breath variation in breathing. In studies at night, apneas were nearly all central and occurred in the awake state. Breath-to-breath variation in breathing was greater (P < 0.05) during wakefulness than during non-rapid eye movement sleep. However, one week after the final IA injection, the breathing pattern, breath-to-breath variation, and arterial blood gases and pH were unchanged from baseline, but there was a 20% decrease in respiratory frequency (f) and CO(2) sensitivity (P < 0.05), as well as a 40% decrease in the ventilatory response to hypoxia (P < 0.001). In subsequent histological analysis of the presumed preBötzC region of lesioned goats, it was determined that there was a 90 and 92% reduction from control goats in total and neurokinin-1 receptor neurons, respectively. Therefore, it was concluded that 1) the dysrhythmic effects on breathing are state dependent; and 2) after incremental, near total destruction of the presumed preBötzC region, time-dependent plasticity within the respiratory network provides a rhythm capable of sustaining normal arterial blood gases.

Focal acidosis in the pre-Botzinger complex area of awake goats induces a mild tachypnea

There are widespread chemosensitive areas in the brain with varying effects on breathing. In the awake goat, microdialyzing (MD) 50% CO(2) at multiple sites within the medullary raphe increases pulmonary ventilation (Vi), blood pressure, heart rate, and metabolic rate (Vo(2)) (11), while MD in the rostral and caudal cerebellar fastigial nucleus has a stimulating and depressant effect, respectively, on these variables (17). In the anesthetized cat, the pre-Bötzinger complex (preBötzC), a hypothesized respiratory rhythm generator, increases phrenic nerve activity after an acetazolamide-induced acidosis (31, 32). To gain insight into the effects of focal acidosis (FA) within the preBötzC during physiological conditions, we tested the hypothesis that FA in the preBötzC during wakefulness would stimulate breathing, by increasing respiratory frequency (f). Microtubules were bilaterally implanted into the preBötzC of 10 goats. Unilateral MD of mock cerebral spinal fluid equilibrated with 6.4% CO(2) did not affect Vi, tidal volume (Vt), or f. Unilateral MD of 25 and 50% CO(2) significantly increased Vi and f by 10% (P < 0.05, n = 10, 17 trials), but Vt was unaffected. Bilateral MD of 6.4, 25, or 50% CO(2) did not significantly affect Vi, Vt, or f (P > 0.05, n = 6, 6 trials). MD of 80% CO(2) caused a 180% increase in f and severe disruptions in airflow (n = 2). MD of any level of CO(2) did not result in any significant changes in mean arterial blood pressure, heart rate, or Vo(2). Thus the data suggest that the preBötzC area is chemosensitive, but the responses to FA at this site are unique compared with other chemosensitive sites.

The cerebellar fastigial nucleus contributes to CO2-H+ ventilatory sensitivity in awake goats

The purpose of this study was to test the hypothesis that an intact cerebellar fastigial nucleus (CFN) is an important determinant of CO(2)-H(+) sensitivity during wakefulness. Bilateral, stainless steel microtubules were implanted into the CFN (N=9) for injection (0.5-10 microl) of the neurotoxin ibotenic acid. Two or more weeks after implantation of the microtubules, eupneic breathing and CO(2)-H(+) sensitivity did not differ significantly (P>0.10) from pre-implantation conditions. Injection of ibotenic acid (50 mM) did not significantly alter eupneic Pa(CO2) (P>0.10). The coefficient of variation of eupneic Pa(CO2) was 4.0+/-0.6 and 3.7+/-0.4% over the 2 weeks before and after the lesion, respectively. CO(2)-H(+) sensitivity expressed as inspired ventilation/Pa(CO2) decreased from 2.15+/-0.17 pre-lesion to 1.58+/-0.26 l/(min mmHg) 3-6 days post-lesion (P<0.02, -27%). There was no significant (P>0.10) recovery of sensitivity between 7 and 10 days post-lesion. The lesion also increased (P<0.05) the day-to-day variability of this index by nearly 100%. When CO(2) sensitivity was expressed as elevated inspired CO(2)/room air V (I), values at 7%, but not 3 and 5% inspired CO(2), were reduced and more variable (P<0.05) after the ibotenic acid injections. We conclude that during wakefulness, the CFN contributes relatively more to overall ventilatory drive at high relative to low levels of hypercapnia.