Efficient Direct X‑ray Detection and Imaging Based on a Lead-Free Electron Donor–Acceptor MOF

Metal–organic frameworks (MOFs) have recently gained extensive attention as potential materials for direct radiation detection due to their strong radiation absorption, long-range order, and chemical tunability. However, it remains challenging to develop a practical MOF-based X-ray direct detector that possesses high X-ray detection efficiency, radiation stability, and environmental friendliness. The integration of donor–acceptor (D–A) pairs into crystalline MOFs is a powerful strategy for the precise fabrication of multifunctional materials with unique optoelectronic properties. Herein, a new lead-free MOF, Cu2I2(TPPA) (CuI-TPPA, TPPA = tris[4-(pyridine-4-yl)phenyl]amine), with a 6-fold interpenetrated structure is designed and synthesized based on the electron donor–acceptor strategy. CuI-TPPA has a large mobility-lifetime (μτ) product of 5.8 × 10–4 cm2 V–1 and a high detection sensitivity of 73.1 μC Gyair–1 cm–2, surpassing that of commercial α-Se detectors. Moreover, the detector remains fairly stable with only a 2% reduction in photocurrent under continuous bias irradiation conditions with a total dose of over 42.83 Gyair. The CuI-TPPA/poly(vinylidene fluoride) flexible composite X-ray detector films are successfully manufactured with different thicknesses. Through multifaceted assessments, the optimal thickness is found with a high detection sensitivity of up to 143.6 μC Gyair–1 cm–2. As proof-of-concept, 11 × 9 pixelated X-ray detectors are fabricated on the same composite film to realize X-ray direct imaging. This work opens up potential applications of MOFs in environmentally friendly and wearable devices for direct X-ray detection and imaging

Efficient Direct X‑ray Detection and Imaging Based on a Lead-Free Electron Donor–Acceptor MOF

Metal–organic frameworks (MOFs) have recently gained extensive attention as potential materials for direct radiation detection due to their strong radiation absorption, long-range order, and chemical tunability. However, it remains challenging to develop a practical MOF-based X-ray direct detector that possesses high X-ray detection efficiency, radiation stability, and environmental friendliness. The integration of donor–acceptor (D–A) pairs into crystalline MOFs is a powerful strategy for the precise fabrication of multifunctional materials with unique optoelectronic properties. Herein, a new lead-free MOF, Cu2I2(TPPA) (CuI-TPPA, TPPA = tris[4-(pyridine-4-yl)phenyl]amine), with a 6-fold interpenetrated structure is designed and synthesized based on the electron donor–acceptor strategy. CuI-TPPA has a large mobility-lifetime (μτ) product of 5.8 × 10–4 cm2 V–1 and a high detection sensitivity of 73.1 μC Gyair–1 cm–2, surpassing that of commercial α-Se detectors. Moreover, the detector remains fairly stable with only a 2% reduction in photocurrent under continuous bias irradiation conditions with a total dose of over 42.83 Gyair. The CuI-TPPA/poly(vinylidene fluoride) flexible composite X-ray detector films are successfully manufactured with different thicknesses. Through multifaceted assessments, the optimal thickness is found with a high detection sensitivity of up to 143.6 μC Gyair–1 cm–2. As proof-of-concept, 11 × 9 pixelated X-ray detectors are fabricated on the same composite film to realize X-ray direct imaging. This work opens up potential applications of MOFs in environmentally friendly and wearable devices for direct X-ray detection and imaging

Additional file 1: of Computational simulation indicates that moderately high-frequency ventilation can allow safe reduction of tidal volumes and airway pressures in ARDS patients

Simulation model description and optimisation algorithm description

Additional file 1: of Hemodynamic effects of lung recruitment maneuvers in acute respiratory distress syndrome

Model and Model fitting description and calibration. Contains description of the pulmonary model, cardiac model, cardio pulmonary interactions, model calibration to a healthy state and disease state, selection of patient data, assignment of baseline model parameters, model parameter configuration using optimization, list of parameters used for model fitting, model parameters for simulated patients and healthy state, hemodynamic and pulmonary outputs. (PDF 1930 kb

Additional file 1: of Hemodynamic effects of lung recruitment maneuvers in acute respiratory distress syndrome

Model and Model fitting description and calibration. Contains description of the pulmonary model, cardiac model, cardio pulmonary interactions, model calibration to a healthy state and disease state, selection of patient data, assignment of baseline model parameters, model parameter configuration using optimization, list of parameters used for model fitting, model parameters for simulated patients and healthy state, hemodynamic and pulmonary outputs. (PDF 1930 kb

The <i>dwt1</i> mutant plants display morphological defects.

<p>A. Morphology of the wild type and <i>dwt1</i> plants after heading. Bar = 10 cm. B. Mature main shoots with leaves removed from the culm. Arrowheads point to the nodes. Bar = 10 cm. C. Mature tillers with leaves removed from the culm. Arrowheads point to the nodes. Bar = 10 cm. D. Close-up view of the internodes after heading stage. From left to right: the 2^nd node of the wild type, the 2^nd internode, the 2^nd and 3^rd internodes, the 2^nd, 3^rd, and 4^th internodes of <i>dwt1</i> mutant. Bar = 0.5 cm. E. Frequency of normal and short internodes in wild-type and <i>dwt1</i> main shoot (MS) and tiller shoot (TS). 2^nd: only 2^nd internode short; 2^nd, 3^rd: both 2^nd and 3^rd internodes short; 2^nd, 3^rd, 4^th: all 2^nd, 3^rd, 4^th internodes short. Elongation pattern of main shoots and tillers of both wild type and <i>dwt1</i> mutants were evaluated at mature stage, and 25 main shoots and 100 tillers of wild type and 25 main shoots and 143 tillers of mutant plants were observed. F. Morphology of panicles from the main shoot (MS) and tillers (TS) of wild type (WT) and <i>dwt1</i> after heading. Bar = 2 cm.</p

The replanted main shoot and tiller of <i>dwt1</i> reproduce the main-shoot-dominance phenotype.

<p>A. Morphology of mature plants developed from replanted main shoot of the wild type (RPwM), replanted tillers of the wild type (RPwT), replanted main shoot of <i>dwt1</i> (RPdM) and replanted tillers of <i>dwt1</i> (RPdT). Bar = 5 cm. B. The culm length of both main shoots (MS) and tillers (TS) of replanted plants. Culm length of 15 main shoots and 60 tillers of wild-type plants, 15 main shoots and 55 tillers of mutant plants were measured at mature stage. Error bars indicate SD, and the very significant differences from the wild type are marked (**p<0.01, Student's <i>t</i> test).</p

The <i>dwt1</i> tiller internodes are insensitive to GA treatment, and <i>DWT1</i> may act downstream of SLR1 in the tiller internode elongation.

<p>A. Morphological comparison of the wild type and <i>dwt1</i> treated with mock solution or 100 µM GA₃. 20 plants were uses for each treatment and representative images are shown. Bar = 10 cm. B. The second internodes of the wild type and <i>dwt1</i> treated with mock solution or 100 µM GA₃. Representative images of tiller internodes are shown. Bar = 1 cm. C. The internode length of the wild type and <i>dwt1</i> treated with mock solution or 100 µM GA₃. Length of 20 tiller internodes were measured 20 days after treatment. Error bars indicate SD, and the significant differences from no GA treated control are marked (** P<0.01, Student's <i>t</i> test). D. qRT–PCR analysis of <i>OsGA20OX</i> genes in the elongating internode of the wild type and <i>dwt1</i> treated with mock solution or 100 µM GA₃. <i>EF1α</i> gene was used as a control. This experiment was biologically repeated three times, and 5 internodes (Length = 5 mm) were used for each biological repeat. Error bars indicate SD. Significant differences from the wild type are marked (* P<0.05, ** P<0.01, Student's <i>t</i> test). E. Phenotype of basal internodes in the wild type, <i>dwt1</i>, <i>slr1</i> and <i>dwt1 slr1</i>double mutant. Arrows point to the nodes on the culm. Bar = 1 cm.</p

Expression pattern of DWT1 transcripts and proteins.

<p>A. qRT-PCR analysis of <i>DWT1</i> gene expression levels in the wild-type tissues including coleoptiles (36 h after seed germination), root tips, mature leaf and sheath, the second internode during elongating (1 cm in length), segments of the upper (U), middle (M), and lower (L) parts of the second internode with 3 cm in length, dormant tiller bud, panicle (less than 1 cm in length), spikelet at stage Sp8 during development of pistil <a href="http://www.plosgenetics.org/article/info:doi/10.1371/journal.pgen.1004154#pgen.1004154-Ikeda2" target="_blank">[63]</a>, young embryo (10 days after fertilization), and callus with 20–days regeneration. Rice <i>ACTIN1</i> (<i>OsACTIN1</i>) was used as a control. Error bars indicate SD. n = 3. B. qRT-PCR analysis of <i>DWT1</i> gene expression levels in young panicle of wild type. This experiment was biologically repeated three times, and 30 young panicles of the main shoot (MP, Length = 5 mm), and the tiller (TP, Length = 5 mm) respectively were used in each test. Error bars indicate SD, and the significant differences from panicle of main shoot are marked (**p<0.01, Student's <i>t</i> test). C–L. <i>In situ</i> hybridization of <i>DWT1</i>. Signals were detected in the primary branch meristem (E), secondary branch meristem (C, F), top portion of the panicle (G), shoot apical and radical apical of young embryo (I), and endodermis and exodermis of root tip (K). D, H, J and L were corresponding sections hybridized with the sense probe.I,II,III,IV, the first, second, third and the forth internode, respectively; pb, primary branch meristem; sb, secondary branch meristem; yl, young leave; fm, floral meristem; ifm, inflorescence meristem; exd, exodermis layer; end, endodermis layer. M–R. YFP fluorescence image of the branch meristem (M–O) and the internode (P–R) in transgenic plants expressing <i>pDWT1:DWT1-YFP</i>. M and P are fluorescence image, N and Q are light view, O and R are overlapping of fluorescence image and light view. S. Western-blot analysis of DWT1 protein levels. DWT1 protein was analyzed by immunoblotting using an anti-DWT1 antibody using mature flag leaf (L, 3 leaves from 3 different plants), elongating internodes (IN_A, length = 0.5 cm; IN_B, length = 3 cm, 10 internodes from different plants) and young panicle (P, length less than 2 mm, 50 panicles from different plants). β-tubulin was used as a control. These experiments were biologically repeated three times.</p

<i>DWT1</i> affects the expression of genes related to cell division and cell elongation.

<p>A. Identification of GO biological process categories for the genes differentially expressed in <i>dwt1</i> shorter internodes. The negative logarithm (base 10) of the adjusted P value was used as the bar length. B. qRT-PCR confirmed the differential expression of genes involved in cell division and cell elongation in the elongating second internode of the wild type and <i>dwt1</i>. . Rice <i>ELONGATION FACTOR 1 ALPHA</i> (<i>EF1α</i>) gene was used as a control. This experiment was biologically repeated three times, and 10 elongating second internodes of tillers (Length = 0.5 cm) were used for each biological repeat. Error bars indicate SD, and the significant differences from the wild type are marked (**p<0.01, Student's <i>t</i> test).</p