Task: Schema-Matching (source dataset: assays)

Task: 
Please identify the matching columns between Table A and Table B. For each column in Table A, specify the corresponding column in Table B. If a column in A has no corresponding column in Table B, you can map it to null. Represent each column mapping using a pair of column headers in a list, i.e., [Table A Column, Table B column or null]. Provide the mapping for each column in Table A and return all mappings in a list.

No explanation and return the matching columns in a structured JSON format: {"column_mappings": <a list of column pairs>}.

TableA:
|   assay_id | assay_strain   | variant_id   | assay_tissue   |    tid | src_assay_id   |   doc_id | description                                                                                                 | assay_type   | assay_test_type   | assay_category   | assay_organism   | assay_tax_id   | assay_cell_type   |
|-----------:|:---------------|:-------------|:---------------|-------:|:---------------|---------:|:------------------------------------------------------------------------------------------------------------|:-------------|:------------------|:-----------------|:-----------------|:---------------|:------------------|
|          1 |                |              |                |  12052 |                |    11087 | The compound was tested for the in vitro inhibition of platelet 12-lipoxygenase at a concentration of 30 uM | B            |                   |                  |                  |                |                   |
|          2 |                |              |                |  22226 |                |      684 | Compound was evaluated for its ability to mobilize calcium in 1321NI cells                                  | F            |                   |                  |                  |                |                   |
|          3 |                |              |                |  22226 |                |    15453 |                                                                                                             | B            |                   |                  |                  |                |                   |
|          4 |                |              |                | 104729 |                |    17841 | Binding affinity against A2 adenosine receptor in bovine striatal membranes using [3H]CGS-21680             | B            |                   |                  | Bos taurus       | 9913.0         |                   |
|          5 |                |              |                |  80001 |                |    17430 | In vitro cell cytotoxicity against 143-B cell lines (Human osteosarcoma cell line)                          | F            |                   |                  | Homo sapiens     | 9606.0         | 143B              |
|          6 |                |              |                |  80001 |                |    17430 | In vitro cell cytotoxicity against 143-B cell lines (Human osteosarcoma cell line)                          | F            |                   |                  | Homo sapiens     | 9606.0         | 143B              |
|          7 |                |              |                |  80001 |                |    13799 | Cytotoxic Activity was evaluated against 143B (TK-) tumor cells                                             | F            |                   |                  | Mus musculus     | 10090.0        | 143B              |
|          8 |                |              |                |  80001 |                |    17774 | In vitro cell cytotoxicity was determined against 143B cell line                                            | F            |                   |                  | Homo sapiens     | 9606.0         | 143B              |
|          9 |                |              |                |  80001 |                |     3801 | Inhibitory activity against tumor osteosarcoma cell line 143B after 72 hr continuous exposure to compound   | F            |                   |                  | Homo sapiens     | 9606.0         | 143B              |
|         10 |                |              |                |  80001 |                |    17430 | In vitro cell cytotoxicity against 143B-LTK cell lines expressed in HSV-1 TK                                | F            |                   |                  | Homo sapiens     | 9606.0         | 143B              |

TableB:
|   assays_ss_d | assays_ss_strn   | assays_vrnt_d   | assays_ss_tss   |   assays_td | assays_src_ss_d   | assays_ss_sbclllr_frctn   | assays_rltnshp_tp   |   assays_cnfdnc_scr | assays_crtd_b   |   assays_src_d | assays_chmbl_d   | assays_cll_d   | assays_b_frmt   | assays_tss_d   |
|--------------:|:-----------------|:----------------|:----------------|------------:|:------------------|:--------------------------|:--------------------|--------------------:|:----------------|---------------:|:-----------------|:---------------|:----------------|:---------------|
|          7524 |                  |                 | Kidney          |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618647     |                | BAO_0000218     | 2113.0         |
|          7525 |                  |                 | Kidney          |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618648     |                | BAO_0000218     | 2113.0         |
|          7526 |                  |                 | Kidney          |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618649     |                | BAO_0000218     | 2113.0         |
|          7527 |                  |                 | Liver           |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618650     |                | BAO_0000218     | 2107.0         |
|          7528 |                  |                 | Liver           |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618651     |                | BAO_0000218     | 2107.0         |
|          7529 |                  |                 | Liver           |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL876497     |                | BAO_0000218     | 2107.0         |
|          7530 |                  |                 | Lung            |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618652     |                | BAO_0000218     | 2048.0         |
|          7531 |                  |                 | Lung            |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618653     |                | BAO_0000218     | 2048.0         |
|          7532 |                  |                 | Lung            |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618654     |                | BAO_0000218     | 2048.0         |
|          7533 |                  |                 |                 |       50597 |                   |                           | N                   |                   1 | Intermediate    |              1 | CHEMBL618655     |                | BAO_0000218     |                |



source_headers: assay_id
assay_strain
variant_id
assay_tissue
tid
src_assay_id
target_headers: assays_ss_d
assays_ss_strn
assays_vrnt_d
assays_ss_tss
assays_td
assays_src_ss_d
column_mappings: assay_id
assays_ss_d
assay_strain
assays_ss_strn
variant_id
assays_vrnt_d
assay_tissue
assays_ss_tss
tid
assays_td
src_assay_id
assays_src_ss_d
output: {"column_mappings": [["assay_id", "assays_ss_d"], ["assay_strain", "assays_ss_strn"], ["variant_id", "assays_vrnt_d"], ["assay_tissue", "assays_ss_tss"], ["tid", "assays_td"], ["src_assay_id", "assays_src_ss_d"], ["doc_id", null], ["description", null], ["assay_type", null], ["assay_test_type", null], ["assay_category", null], ["assay_organism", null], ["assay_tax_id", null], ["assay_cell_type", null]]}