Liquid Architecture

As defined by Zygmunt Bauman, contemporary society is in a liquid state of existence, exhibiting the characteristics of fragility, temporariness, vulnerability, and an inclination to constant change. Society suffers from an acute malaise: one that leaves architecture ill-suited to contend with rapid and uncertain changes. The principles of architectural modernism have traditionally meant to present an ephemeral snapshot of the creativity of the era, however, the style of modernism quickly became monumentalized and thus became misaligned with the initial ideological spirit of a fluid and light modernity. The dilemma between “modern” and “-ism” shows that modernist architecture is merely an image of modernity, but was not itself actually modern. In today’s liquid modernity, architecture needs to become synchronized with the true character of liquidity and be responsive to and reflective of the characteristics of this hyper-modernity. To contend with the plasticity of society, architecture also needs to instill within itself the nature of liquidity, ephemerality, flexibility, adaptability, and resiliency to rapid and constant change, and embody the liquid spirit of the times. Liquid architecture aims to respond to this dialectic of ephemerality, fragility, and ambivalence, to reconstruct the fundamentals of architecture itself

Photodetectors Based on Two-Dimensional Layer-Structured Hybrid Lead Iodide Perovskite Semiconductors

Hybrid lead iodide perovskite semiconductors have attracted intense research interests recently because of their easy fabrication processes and high power conversion efficiencies in photovoltaic applications. Layer-structured materials have interesting properties such as quantum confinement effect and tunable band gap due to the unique two-dimensional crystalline structures. ⟨100⟩-oriented layer-structured perovskite materials are inherited from three-dimensional ABX₃ perovskite materials with a generalized formula of (RNH₃)₂(CH₃NH₃)_<i>n</i>−1<i>M</i>_<i>n</i>X_3<i>n</i>+1, and adopt the Ruddlesden–Popper type crystalline structure. Here we report the synthesis and investigation of three layer-structured perovskite materials with different layer numbers: (C₄H₉NH₃)₂PbI₄ (n = 1, one-layered perovskite), (C₄H₉NH₃)₂(CH₃NH₃)­Pb₂I₇ (<i>n</i> = 2, two-layered perovskite) and (C₄H₉NH₃)₂(CH₃NH₃)₂Pb₃I₁₀ (<i>n</i> = 3, three-layered perovskite). Their photoelectronic properties were investigated in related to their molecular structures. Photodetectors based on these two-dimensional (2D) layer-structured perovskite materials showed tunable photoresponse with short response time in milliseconds. The photodetectors based on three-layered perovskite showed better performances than those of the other two devices, in terms of output current, responsivity, <i>I</i>_light/<i>I</i>_dark ratio, and response time, because of its smaller optical band gap and more condensed microstructure comparing the other two materials. These results revealed the relationship between the molecular structures, film microstructures and the photoresponse properties of 2D layer-structured hybrid perovskites, and demonstrated their potentials as flexible, functional, and tunable semiconductors in optoelectronic applications, by taking advantage of their tunable quantum well molecular structure

Illustration of surgical management for tuberculous spondylitis through transforaminal thoracic (lumbar), interbody fusion and debridement.

<p>The pictures were reproduced with the permission of the Hunan Publishing House.</p

Scatter plot shows the ODI scores of every patient preoperatively and at the last follow-up, with significant difference (t = 22.79, P <0.0001).

<p>The same color of the dot represents the same patient.</p

Requirement for Drosophila SNMP1 for Rapid Activation and Termination of Pheromone-Induced Activity

<div><p>Pheromones are used for conspecific communication by many animals. In Drosophila, the volatile male-specific pheromone 11-<i>cis</i> vaccenyl acetate (cVA) supplies an important signal for gender recognition. Sensing of cVA by the olfactory system depends on multiple components, including an olfactory receptor (OR67d), the co-receptor ORCO, and an odorant binding protein (LUSH). In addition, a CD36 related protein, sensory neuron membrane protein 1 (SNMP1) is also involved in cVA detection. Loss of SNMP1 has been reported to eliminate cVA responsiveness, and to greatly increase spontaneous activity of OR67d-expressing olfactory receptor neurons (ORNs). Here, we found the <i>snmp1¹</i> mutation did not abolish cVA responsiveness or cause high spontaneous activity. The cVA responses in <i>snmp1</i> mutants displayed a delayed onset, and took longer to reach peak activity than wild-type. Most strikingly, loss of SNMP1 caused a dramatic delay in signal termination. The profound impairment in signal inactivation accounted for the previously reported “spontaneous activity,” which represented continuous activation following transient exposure to environmental cVA. We introduced the silk moth receptor (BmOR1) in OR67d ORNs of <i>snmp1¹</i> flies and found that the ORNs showed slow activation and deactivation kinetics in response to the BmOR1 ligand (bombykol). We expressed the bombykol receptor complex in Xenopus oocytes in the presence or absence of the silk moth SNMP1 (BmSNMP) and found that addition of BmSNMP accelerated receptor activation and deactivation. Our results thus clarify SNMP1 as an important player required for the rapid kinetics of the pheromone response in insects.</p></div

Clinical details of surgical group.

<p>M male; F female; LV last visit; Pre preoperative; Post postoperative; T thoracic; L lumbar; CT cervicothoracic; TL thoracolumbar; TTIF transforaminal thoracic debridement, interbody fusion; TLIF transforaminal lumbar debridement, interbody fusion; AP anterior debridement and posterior instrumentation. # indicates a statistically significant difference between preoperation and postoperation (t = 8.410, P<0.05); * indicates that there is no significant difference comparing postoperative and at final visit values (t = 1.902, P = 0.07).</p

Close application of 100% cVA elicited responses in the <i>lush¹</i>,<i>snmp1¹</i> double mutants.

<p>(A) Representative traces of OR67d ORNs from the indicated genotypes in response to stimulation with 100% cVA applied at close range. The 1 sec application of cVA is indicated by the bar above the traces. (B) Response dynamics of OR67d ORNs from the indicated genotypes in response to 100% cVA applied using the close range approach (n = 14–18). <i>snmp1¹</i> data were regenerated from <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004600#pgen-1004600-g002" target="_blank">Figure 2</a>. Means ±S.E.M.</p

A 26-year-old woman with multilevel noncontiguous cervicothoracic tuberculous spondylitis underwent posterior instrumentation and anterior debridement, graft fusion plus anterior instrumentation.

<p>Note the marked improvement of spinal stability and solid bone fusion when comparing her preoperative and latest films. (a) Preoperative X-ray films of cervical spine show bone destruction of the C7 and T1 vertebral bodies. (b) Preoperative CT shows tuberculosis cavities and paravertebral abscess at C7-T1 and T2 and limited involvement at T6. (c) Preoperative sagittal T1W MRI (left) showing involvement of C7-T2 with collapse of the C7 and T2 vertebras and paravertebral abscess, Gd-DTPA-enhanced T1W sagittal MRI (right) showing enhancements of the inflammatory vertebral bodies and tissue. (d) Standing anteroposterior and lateral radiographs immediately after operation. (e) X-ray films and sagittal CT of cervical spine show grafts union at the final follow-up of 36 months.</p

High cVA levels elicited weak responses in <i>snmp1¹</i>, which displayed slow activation and deactivation kinetics.

<p>The SSRs were from female flies of the indicated genotypes. (A) Representative SSRs obtained from OR67d ORNs stimulated with cVA for 1 sec (indicated by the horizontal black bar) using the conventional odorant delivery approach. (B) Action potential frequencies as a function of the concentration of the applied cVA using the conventional odorant delivery method. (C) Representative traces showing the responses from OR67d ORNs evoked by close-range application of 100% cVA (indicated by the horizontal bar above the trace). The cVA was puffed onto the antenna through a pipette tip placed 3 mm away from the fly antenna. The flies expressing <i>UAS</i>-<i>snmp1</i> under the control of the <i>snmp1-Gal4</i> transgene were in a <i>snmp1¹</i> background. (D) Quantification of peak firing rates following close-range application of cVA. n = 17–20. (E) Quantification of the onset delays of the responses to close-range stimulation with cVA. (F) The upper graph shows the duration of the firing of OR67d neurons after close-range application of 100% cVA. The estimated times required for a 50% reduction of the evoked firing rates (<i>t</i>_1/2) are shown (n = 17–20). The frequencies (spikes/sec) were binned every 0.5 sec. Therefore, the <i>t</i>_1/2 were rounded to the nearest 0.5 sec. The traces in the lower graph plot were derived from the upper panel, and were normalized to their respective peak firing rates. Means ±S.E.M. The asterisks indicate significant differences from wild-type and rescue flies (**<i>p<0.01</i>) based on unpaired Student <i>t</i>-test for comparing pairs of data (B and D) and ANOVA with the Bonferroni-Holm <i>post hoc</i> test for comparing multiple samples (E).</p

Effects of prior exposure either to males or to cVA on “spontaneous” spiking activity.

<p>Single sensillum recordings (SSRs) were from trichoid sensilla (T1), which contain an OR67d-expressing ORN. Neither the wild-type nor the <i>snmp1¹</i> flies were exposed to cVA during the recordings. (A) Representative traces showing firing activities from wild-type and <i>snmp1¹</i> females, which were either reared in isolation or in groups with males, as indicated. (B) Mean firing rates elicited by grouped or isolated wild-type and <i>snmp1¹</i> females. n = 15–18. (C) Average spiking activities of OR67d neurons from isolated male or female <i>snmp1¹</i> flies. The ages of the flies are indicated. n = 8–10. (D) Wild-type and <i>snmp1¹</i> females were exposed to cVA or the vehicle (paraffin oil) for 24 hrs immediately prior to the recordings. n = 16–18. Mean ±S.E.M. The asterisks indicate significant differences between groups (*<i>p</i><0.05, **<i>p</i><0.01) using ANOVA with Bonferroni-Holm <i>post hoc</i> test to compare multiple samples (B) and the unpaired Student <i>t</i>-test for comparing pairs of data (C and D). NS, no significant difference.</p